This is part of the sidequest Scavenger Hunt: The Yaoi Project which can be started by talking to Craig’s dad after completing the main quest The Chains of Super Craig. There is a total of 40 Yaoi Fan Art scattered in various locations in town. Craig’s dad will give you a reward for collecting 10, 25, and all 40 fanarts.
If you solve the puzzle in Bebe’s basement (will require Sandblaster), you’ll get an access to the Yaoi Fanart map which will indicate their general locations. For the exact location of each fanart and how to get them, you can refer to the list below, using Bebe’s map as reference.
Some of the fanarts are hidden in locations that you can access using specific timefarts and buddy powers so you don't have to bother collecting all of them until later in the game.
For the complete list of these fanarts, you can refer to this link
and this link