update alt-text

Author: tfitzmac

articles/azure-resource-manager/management/preview-features.md

@@ -30,27 +30,27 @@ The portal only shows a preview feature when the service that owns the feature h
 1. Sign in to the [Azure portal](https://portal.azure.com/).
 1. In the search box, enter _subscriptions_ and select **Subscriptions**.
 
-    :::image type="content" source="./media/preview-features/search.png" alt-text="Azure portal search.":::
+    :::image type="content" source="./media/preview-features/search.png" alt-text="Screenshot of Azure portal search box with 'subscriptions' entered.":::
 
 1. Select the link for your subscription's name.
 
-    :::image type="content" source="./media/preview-features/subscriptions.png" alt-text="Select Azure subscription.":::
+    :::image type="content" source="./media/preview-features/subscriptions.png" alt-text="Screenshot of Azure portal with subscription selection highlighted.":::
 
 1. From the left menu, under **Settings** select **Preview features**.
 
-    :::image type="content" source="./media/preview-features/preview-features-menu.png" alt-text="Azure preview features menu.":::
+    :::image type="content" source="./media/preview-features/preview-features-menu.png" alt-text="Screenshot of Azure portal with Preview features menu option highlighted.":::
 
 1. You see a list of available preview features and your current registration status.
 
-    :::image type="content" source="./media/preview-features/preview-features-list.png" alt-text="Azure portal list of preview features.":::
+    :::image type="content" source="./media/preview-features/preview-features-list.png" alt-text="Screenshot of Azure portal displaying a list of preview features.":::
 
 1. From **Preview features** you can filter the list by **name**, **State**, or **Type**:
 
     - **Filter by name**: Must contain text from a preview feature's name, not the **Display name**.
     - **State**: Select the drop-down menu and choose a state. The portal doesn't filter by **Unregistered**.
     - **Type**: Select the drop-down menu and choose a type.
 
-    :::image type="content" source="./media/preview-features/filter.png" alt-text="Azure portal filter preview features.":::
+    :::image type="content" source="./media/preview-features/filter.png" alt-text="Screenshot of Azure portal with filter options for preview features.":::
 
 # [Azure CLI](#tab/azure-cli)
 
@@ -169,7 +169,7 @@ Some services require other methods, such as email, to get approval for pending
 1. Select the link for the preview feature you want to register.
 1. Select **Register**.
 
-    :::image type="content" source="./media/preview-features/register.png" alt-text="Azure portal register preview feature.":::
+    :::image type="content" source="./media/preview-features/register.png" alt-text="Screenshot of Azure portal with Register button for a preview feature.":::
 
 1. Select **OK**.
 
@@ -253,7 +253,7 @@ You can unregister preview features from **Preview features**. The **State** cha
 1. Select the link for the preview feature you want to unregister.
 1. Select **Unregister**.
 
-    :::image type="content" source="./media/preview-features/unregister.png" alt-text="Azure portal unregister preview feature.":::
+    :::image type="content" source="./media/preview-features/unregister.png" alt-text="Screenshot of Azure portal with Unregister button for a preview feature.":::
 
 1. Select **OK**.