Isn't this (minus the AI buzzword) what Netflix does? They're constantly using different stills, (supposedly well-)designed for the given user.

Edit: Noted by jsnell elsewhere here: <https://news.ycombinator.com/item?id=40599828>

It's a thing at Netflix! And a pretty extensive and detailed approach

https://www.youtube.com/watch?v=axCBA3VD5dQ

https://netflixtechblog.com/artwork-personalization-c589f074...

That already exists. Built into Google Photos, for example.