The rules are against AI-generated content - I believe that this includes promotional material as well.
Viewing post in It's Jeff! (Dahmer) jam comments
Well, I'll have to find out and fix that, but if I spent two weeks working on a game only to have it disqualified because of the picture I chose to represent it when I had an hour left on the clock... Well, that would be silly, since it has absolutely nothing to do with the making of the game itself, wouldn't it?