It appears to be an old elevator, with wires hanging down. There are 2 windows, one at each side of the door. There appear to be children's drawings scattered all over it, including one of Jester-In-A-Box, as well as a Buster and Freddy poster, wich can honk by clicking on his nose.
The player needs to get inside the elevator to travel to the next and previous floor. To activate the elevator, the player needs to press Space, and wait until it reaches its destination.
The idea of having an elevator in the game might be taken from FNaF: Sister Location.