Photo 1: It seems like the sub would be impaled on the dildo. However, the dildo seems not to be attached on top of the sharp edge shown in photo 2. 
Photo 2: The sub will have to sit on this sharp edge and it will soon become really uncomfortable. 
Photo 3: The third photo is the most clear one. The sub is probably sitting on that edge from photo 2 and he's hooded, blindfolded, probably gagged as well. Something which looks like a posture collar as well. He has to lift himself up so that he doesn't have to sit on the sharp edge. The chain is long enough to allow him to sit down if he wants to, that's very kind of you ;)
Photo 4: If the sub lifts himself up to avoid the sharp edge, he has to lift this weight as well and it's probably attached to his balls. It would be even more humiliating if the keys to his restraints are in there.
Photo 5: Once that box is taken away from under his feet... ouch!

The dildo is really the most difficult part to explain. 