It's his pedofolder. He keeps all those kiddies he turned into with his wands inside there and locked it with a superdupersecret password (in reality it's probably "iloveunicorns" or something like that)
It grew so much it overflows.
Idk. Just a image meme from pixiv [link]
it was small and simple to do and i was..well. Bored. Might as well.
This is pretty fun i'll do it again later when i get back home.