Update alt text

Author: alkohli

azure-stack/hci/upgrade/install-solution-upgrade.md

@@ -96,7 +96,7 @@ On the **Validation** tab, the operation automatically creates Azure resources l
 
 1. Wait for the upgrade to cmplete. The solution upgrade process can take a few hours depending upon the number of nodes in the cluster.
 
-    :::image type="content" source="./media/install-solution-upgrade/upgrade-progress-2.png" alt-text="Screenshot of Upgrade Azure Stack HCI upgrade progress." lightbox="./media/install-solution-upgrade/upgrade-progress-2.png":::
+    :::image type="content" source="./media/install-solution-upgrade/upgrade-progress-2.png" alt-text="Screenshot of Upgrade Azure Stack HCI showing a completed upgrade." lightbox="./media/install-solution-upgrade/upgrade-progress-2.png":::
 
 > [!NOTE]
 > If the upgrade fails, restart the upgrade operation to try again.