Well, this is an interesting one. I had three trees, one a FamilySearch import, one a Gedcom upload, and the new one I had started with the idea I would fully audit my work and source everything and enter it all manually.
I removed the FamilySearch import a couple days ago and the Gedcom import a few minutes ago.
I just went in and the new tree I had started had some media items in it. In all cases they would have been exact duplicates of things I had previously uploaded to FamilySearch and had imported with that tree I deleted, or they were items I selectively pulled over from FamilySearch for the new tree so I didn’t need to upload them. (ie I pulled photos over from FamilySearch but the documents I choose to upload again so I could create sources from them at the same time…)
In the new tree it seems ALL the images have disappeared. The metadata about the images is all still there, just not the actual images themselves.