Thats because I deleted all the unrelated ones a couple hours ago. There were quite a number of them, and I dunno how they got there. Maybe someone meant to do "add to favorites" and instead clicked "add to pool"? They are right next to each other. ::shrugs::
I have no idea what happened but I do know that the extraneous pictures in pool 8 were identical to (now purged) extraneous pictures in the persona 3 pool.