When I publish an ArcGIS Server map service (10.6) to my federated AGS, a Portal item gets automatically created with a cute little thumbnail that's generated from the current extent in ArcGIS Pro when publishing from Pro. Is there a way I can preserve that item thumbnail through future version of the same service? It's great to be able to select "Overwirte Web Layer" in Pro but it would be nice for your those browsing content if the thumbnail didn't change every time you re-publish.
