BGT magic

[◄Chuck►]

Hm, okay. Lets see. Lets assume they made certain that Harry Potter will be chosen every time. All dvd boxed could have HP on the front but some random crap on the backside and put them in the bag that all backsides pointing outward.

However, some little things still puzzling me but two things are sure:
1. Person 1 (who will be left in the final image) is waiting behind the movable screens all the time. At 1:43 he sneaks from behind the screen, behind the "curtain" , one of the hosts is holding.

2. Person 2 is also waiting behind the screen and exchanges position with the host also at 1:43. You can see the host walking behind the screen, but its not him appearing at the other side, its the "surprise guest". That guest then pushes on of the hosts and the two screens off the scene, enters the stage and drops his disguise.

Et voila