If I produce animation stills – Do I need to have my ID attached to the sets as the Art producer to show the art was made by someone 18+?

Where does art stand in the war on porn and the whole 2257 rule?

Also, looking around, I see a lot of art that looks like someone just ran the stamp effect on a photo in photoshop. Does that need the 2257 of the photo used to make the art?