update graphics

Author: cherylmc

articles/vpn-gateway/media/tutorial-create-gateway-portal/gateway-diagram.png

@@ -6,7 +6,7 @@ author: cherylmc
 ms.author: cherylmc
 ms.service: vpn-gateway
 ms.topic: tutorial
-ms.date: 12/20/2022
+ms.date: 04/12/2023
 
 ---
 
@@ -25,7 +25,7 @@ In this tutorial, you learn how to:
 
 The following diagram shows the virtual network and the VPN gateway created as part of this tutorial.
 
-:::image type="content" source="./media/tutorial-create-gateway-portal/gateway-diagram.png" alt-text="VNet and VPN gateway diagram.":::
+:::image type="content" source="./media/tutorial-create-gateway-portal/gateway-diagram.png" alt-text="Diagram of VNet and VPN gateway.":::
 
 ## Prerequisites