Talking Elevator Prank Embarrasses Riders

Why is it that when people set up pranks to embarrass elevator riders it's always so dang funny?

In this prank two guys sit in a room with a monitor, and a microphone so they can talk to the people boarding the elevator.  The things they say and make people do is hilarious, especially when Donald Duck mode is engaged.

Sometimes they speak in a different language and I'm not quite sure what they're saying, but it's still hilarious.