The force is totally with this Jedi, who's opening the elevator doors at will with a quick wave of his arm. It's cool at first...until it's not. We need to get to the other floor, man, and we don't have all day because you've decided to practice your telekinetic powers while you're in the elevator.
Kidding aside, this dude is part of the JesterLads at King's College London, and they're a group of pranksters who have nothing better to do than pull pranks on unsuspecting people all day.
This particular one requires a Jedi (actually, anyone with a hoodie will do) and a guy on the outside, who's responsible for pressing the elevator button in sync with the motion of the Jedi's arm.
Yeah, I bet you already knew that was what they were doing, but some people inside the elevator actually bought it. Lolz.