I expect an extra block has been added to the system and the box houses a block reset switch.
So in the event of a shutdown the blocks need to be reset by making someone attend the bat wing and enabling a resart by visually seeing the track is clear then enabling the block reset if a train is on a block you dont declare it clear.
A typical coster like Colossus has a brake, station, lift and top of lift to breaks is a block.
Obvously various coasters are more in depth like saw smiler ect.