Fixing alt-text

Author: v-gpettibone

includes/iot-hub-include-find-service-connection-string.md

@@ -21,6 +21,6 @@ To get the IoT Hub connection string for the **service** policy, follow these st
 
 1. Under **Shared access keys**, select the copy icon for the **Primary connection string** and save the value.
 
-:::image type="content" source="./media/iot-hub-include-find-service-connection-string/iot-hub-get-connection-string.png" alt-text="Show how to retrieve the connection string" border="true":::
+:::image type="content" source="./media/iot-hub-include-find-service-connection-string/iot-hub-get-connection-string.png" alt-text="Screenshot that shows how to retrieve the connection string" border="true":::
 
 For more information about IoT Hub shared access policies and permissions, see [Access control and permissions](../articles/iot-hub/iot-hub-dev-guide-sas.md#access-control-and-permissions).