You turn to the FOURTH WALL. Never mind all the Rube Goldberg shit for now. That's the elaborate LOCKING MECHANISM that keeps the door to the cell locked. The corpses ensnared in the gears are clowns formerly kept in this cell who tried to solve the puzzle, but got pulled into the machinery and died. Other cells don't have such a complicated locking apparatus. You never know what you're going to get in one of these circus cells, they're all different in stupid ways. You decide to steer clear of the deadly and stupid puzzle.
In the center is the camera, which is embedded in one of the eyes of a robotic RINGMASTER HEAD. Or at least you guess that's what the ringmaster looks like. You've never actually seen him. The head looks kind of ringmastery, so that's probably him. It makes sense given that he'd probably want to keep a watchful eye over his heretical prisoners.