Beveled mirrors and cabinet doors?

Can anyone tell me what these are there are four of them. Mirrors on opposite sides of the door. Or half door? I have look on all the antique sights and can't find anything like them anywhere. I thought maybe they use to lock in to a window or cabinet
I have no clue. They have a latched at the top and at the bottom of them they have a slit that looks like it slides into something?