You can note a few things from this photo. First, the complete lack of windows, clocks or signs. People in these places aren't encouraged, or any way assisted, to keep track of time or to leave the place. Second, the whole place is themed - on King Authur's castle in this case. Everything from the light fittings to the chair backs has a "turrets and knights in armour" theme. Finally, note the black domes in the roof - cameras looking for people cheating. How many can you see in this shot alone? I counted about 30.