Elsewhere, a game was played. This game was an unusual sort of game, and the results are an unusual sort of curiosity, though I should say no more outside of spoiler tags. I thought it would make for an interesting puzzle, so am cross-posting it here with some details hidden.
Here are some pictures. Find the odd one out.
You should be able to solve this problem with visual inspection alone, without the use of analysis tools or internet searches.
The answer to this is going to surprise most people in the world. You should still be able to look at the images, see something suspicious about them, and deduce that something is going on. There is more than one suspicious property you should be looking for.
These images are in a random order and do not encode anything. One of them is just qualitatively different to the others.
The scene depicted is largely arbitrary. The suspicious properties in the images were not intentional.
Attribution spoilers (this is not a hint):
Most of these images are generated by DALL-E 2. DALL-E 2 adds a signature to the bottom right corner of each image, which I censored in order to prevent the game being given away.
Prompts, generations, and the odd one out come from this thread.
Here is a post with all of the prompts and their results.