I believe you need to Beat up to night 3 or 4 to unlock the gallery
Like I said, I'm on the seventh night, and still no gallery. If the creators of this game could help me out, here, I'd greatly appreciate it.
There are VHS tapes randomly hidden in rooms, 0 to 3 per night, grab them and if you win that night, you should get that many unlocks. Can replay earlier nights for an easier time getting the unlocks.
I don't know whether I'm getting VHS tapes or DVDs, but I am getting the little things hidden throughout the levels. And still no gallery.