update alt text

Author: tfitzmac

articles/azure-resource-manager/managed-applications/microsoft-common-checkbox.md

@@ -11,7 +11,7 @@ The CheckBox control lets users check or uncheck an option. The control returns
 
 ## UI sample
 
-:::image type="content" source="./media/managed-application-elements/microsoft-common-checkbox.png" alt-text="Microsoft.Common.CheckBox":::
+:::image type="content" source="./media/managed-application-elements/microsoft-common-checkbox.png" alt-text="Screenshot of Microsoft.Common.CheckBox UI element with a checked and unchecked state.":::
 
 ## Schema
 

articles/azure-resource-manager/managed-applications/microsoft-common-dropdown.md

@@ -15,23 +15,23 @@ The DropDown element has different options that determine its appearance in the
 
 When only a single item is allowed for selection, the control appears as:
 
-:::image type="content" source="./media/managed-application-elements/microsoft-common-dropdown-1.png" alt-text="Screenshot of the Microsoft.Common.DropDown single selection.":::
+:::image type="content" source="./media/managed-application-elements/microsoft-common-dropdown-1.png" alt-text="Screenshot of the Microsoft.Common.DropDown UI element with single selection enabled.":::
 
 When descriptions are included, the control appears as:
 
-:::image type="content" source="./media/managed-application-elements/microsoft-common-dropdown-2.png" alt-text="Screenshot of the Microsoft.Common.DropDown single selection with descriptions.":::
+:::image type="content" source="./media/managed-application-elements/microsoft-common-dropdown-2.png" alt-text="Screenshot of the Microsoft.Common.DropDown UI element with single selection and item descriptions.":::
 
 When multi-select is enabled, the control adds a **Select all** option and checkboxes for selecting more than one item:
 
-:::image type="content" source="./media/managed-application-elements/microsoft-common-dropdown-3.png" alt-text="Screenshot of the Microsoft.Common.DropDown multi-select.":::
+:::image type="content" source="./media/managed-application-elements/microsoft-common-dropdown-3.png" alt-text="Screenshot of the Microsoft.Common.DropDown UI element with multi-select enabled, including a Select all option.":::
 
 Descriptions can be included with multi-select enabled.
 
-:::image type="content" source="./media/managed-application-elements/microsoft-common-dropdown-4.png" alt-text="Screenshot that shows how descriptions can be included with multi-select enabled.":::
+:::image type="content" source="./media/managed-application-elements/microsoft-common-dropdown-4.png" alt-text="Screenshot of the Microsoft.Common.DropDown UI element with multi-select enabled and item descriptions.":::
 
 When filtering is enabled, the control includes a text box for adding the filtering value.
 
-:::image type="content" source="./media/managed-application-elements/microsoft-common-dropdown-5.png" alt-text="Screenshot of the Microsoft.Common.DropDown multi-select with descriptions.":::
+:::image type="content" source="./media/managed-application-elements/microsoft-common-dropdown-5.png" alt-text="Screenshot of the Microsoft.Common.DropDown UI element with multi-select and filtering enabled.":::
 
 ## Schema
 
@@ -90,7 +90,7 @@ When filtering is enabled, the control includes a text box for adding the filter
 
 In the following example, the `defaultValue` is defined using the values of the `allowedValues` instead of the labels. The default value can contain multiple values when `multiselect` is enabled.
 
-:::image type="content" source="./media/managed-application-elements/microsoft-common-dropdown-6.png" alt-text="Screenshot that shows how multiple default values can be included with multi-select enabled":::
+:::image type="content" source="./media/managed-application-elements/microsoft-common-dropdown-6.png" alt-text="Screenshot of the Microsoft.Common.DropDown UI element with multi-select enabled and multiple default values.":::
 
 ```json
 {

articles/azure-resource-manager/managed-applications/microsoft-common-editablegrid.md

@@ -11,7 +11,7 @@ A control for gathering tabular input. All fields within the grid are editable a
 
 ## UI sample
 
-:::image type="content" source="./media/managed-application-elements/microsoft-common-editablegrid.png" alt-text="Microsoft.Common.EditableGrid":::
+:::image type="content" source="./media/managed-application-elements/microsoft-common-editablegrid.png" alt-text="Screenshot of Microsoft.Common.EditableGrid UI element with editable fields and varying rows.":::
 
 ## Schema
 

articles/azure-resource-manager/managed-applications/microsoft-common-fileupload.md

@@ -11,7 +11,7 @@ A control that allows a user to specify one or more files to upload.
 
 ## UI sample
 
-![Microsoft.Common.FileUpload](./media/managed-application-elements/microsoft-common-fileupload.png)
+:::image type="content" source="./media/managed-application-elements/microsoft-common-fileupload.png" alt-text="Screenshot of Microsoft.Common.FileUpload UI element in action.":::
 
 ## Schema
 

articles/azure-resource-manager/managed-applications/microsoft-common-infobox.md

@@ -11,7 +11,7 @@ A control that adds an information box. The box contains important text or warni
 
 ## UI sample
 
-![Microsoft.Common.InfoBox](./media/managed-application-elements/microsoft-common-infobox.png)
+:::image type="content" source="./media/managed-application-elements/microsoft-common-infobox.png" alt-text="Screenshot of Microsoft.Common.InfoBox UI element displaying important text or warnings.":::
 
 
 ## Schema

articles/azure-resource-manager/managed-applications/microsoft-common-optionsgroup.md

@@ -14,7 +14,7 @@ The OptionsGroup control lets users select one option from two or more choices.
 
 ## UI sample
 
-:::image type="content" source="./media/managed-application-elements/microsoft-common-optionsgroup-2.png" alt-text="Microsoft.Common.OptionsGroup":::
+:::image type="content" source="./media/managed-application-elements/microsoft-common-optionsgroup-2.png" alt-text="Screenshot of Microsoft.Common.OptionsGroup UI element with vertically aligned radio buttons.":::
 
 ## Schema
 

articles/azure-resource-manager/managed-applications/microsoft-common-passwordbox.md

@@ -11,7 +11,7 @@ A control that can be used to provide and confirm a password.
 
 ## UI sample
 
-![Microsoft.Common.PasswordBox](./media/managed-application-elements/microsoft-common-passwordbox.png)
+:::image type="content" source="./media/managed-application-elements/microsoft-common-passwordbox.png" alt-text="Screenshot of Microsoft.Common.PasswordBox UI element.":::
 
 ## Schema
 

articles/azure-resource-manager/managed-applications/microsoft-common-section.md

@@ -11,7 +11,7 @@ A control that groups one or more elements under a heading.
 
 ## UI sample
 
-![Microsoft.Common.Section](./media/managed-application-elements/microsoft-common-section.png)
+:::image type="content" source="./media/managed-application-elements/microsoft-common-section.png" alt-text="Screenshot of Microsoft.Common.Section UI element with a heading and grouped elements.":::
 
 ## Schema
 

articles/azure-resource-manager/managed-applications/microsoft-common-serviceprincipalselector.md

@@ -19,17 +19,17 @@ The default view is determined by the values in the `defaultValue` property and
 
 If you want to register a new application, select **Change selection** and the **Register an application** dialog box is displayed. Enter **Name**, **Supported account type**, and select the **Register** button.
 
-:::image type="content" source="./media/managed-application-elements/microsoft-common-serviceprincipal-default.png" alt-text="Microsoft.Common.ServicePrincipalSelector initial view.":::
+:::image type="content" source="./media/managed-application-elements/microsoft-common-serviceprincipal-default.png" alt-text="Screenshot of Microsoft.Common.ServicePrincipalSelector initial view with default application or create new option.":::
 
 After you register a new application, use the **Authentication Type** to enter a password or certificate thumbprint.
 
-:::image type="content" source="./media/managed-application-elements/microsoft-common-serviceprincipal-authenticate.png" alt-text="Microsoft.Common.ServicePrincipalSelector authentication.":::
+:::image type="content" source="./media/managed-application-elements/microsoft-common-serviceprincipal-authenticate.png" alt-text="Screenshot of Microsoft.Common.ServicePrincipalSelector authentication options after registering a new application.":::
 
 ### Use existing application
 
 To use an existing application, choose **Select Existing** and then select **Make selection**. Use the **Select an application** dialog box to search for the application's name. From the results, select the the application and then the **Select** button. After you select an application, the control displays the **Authentication Type** to enter a password or certificate thumbprint.
 
-:::image type="content" source="./media/managed-application-elements/microsoft-common-serviceprincipal-existing.png" alt-text="Microsoft.Common.ServicePrincipalSelector select existing application.":::
+:::image type="content" source="./media/managed-application-elements/microsoft-common-serviceprincipal-existing.png" alt-text="Screenshot of Microsoft.Common.ServicePrincipalSelector with select existing application option and authentication type displayed.":::
 
 ## Schema
 

articles/azure-resource-manager/managed-applications/microsoft-common-slider.md

@@ -11,7 +11,7 @@ The Slider control lets users select from a range of allowed values.
 
 ## UI sample
 
-:::image type="content" source="./media/managed-application-elements/microsoft-common-slider.png" alt-text="Microsoft.Common.Slider":::
+:::image type="content" source="./media/managed-application-elements/microsoft-common-slider.png" alt-text="Screenshot of Microsoft.Common.Slider UI element with a range of allowed values.":::
 
 ## Schema