It’s showing the result of this vandalism (even though it was reverted basically instantly).

Thanks for the report! At a guess, the image might be coming from this edit. It was only live on the page for 24 seconds before being reverted, but I'm guessing PageImages must still be caching it somewhere.

Oops, phab-conflicted with you, @Lucas_Werkmeister_WMDE :P
Untagging PageImages as I think you're probably correct in tagging Page-Previews instead - the PageImages API isn't returning the 'three ghosts' image for the page, but the page preview is still displaying it for me.

Yeah, the fashion house’s page image as shown on action=info looks correct.

This has also happened before – I see T382231 on the board, and it also happened to me at some point a few weeks ago, where the preview referenced an already-deleted image on Commons. (I couldn’t figure out at the time where the vandalism had happened – it didn’t seem to be on the article itself nor on any of the used templates I checked.) But maybe this example here is a more useful test case.

REST base summary API provided by the mobile content service has its own validation so it takes a little longer. I'm not sure if there is anything actionable here unfortunately.