Conductors help the musicians count and when to change volume. Also they help the musicians come in at the right time or to stop
This is probably a joke but I'll answer anyway
By 'cheeks' they mean buttocks so by "making them clap" is referring to them being so big/thick that they clap or make noise when you walk or move around or something.
I probably got played lol but whatever
The Raft of the Medusa has a triangular composition, and the hand gestures, body movement and clothing movement all points up towards the top of the triangle, where people are raising a flag to be rescued from the sinking raft.
