Camera 4 where are you !(Whats the LINK)

[Chip Chester]

The riser and stairs behind the box are tall enough for the stairs to lift up (like a hatchback), and then first camera, then folded pedestal to be stowed beneath, along with the helper.

Mere presence of the observer doesn't mean he prevents anything from happening. He could be an instant accomplice, with the magician "counting on" his discretion. And, if the magician himself picks the observer from the audience, it's probably not really an audience member.

You can also see well into the box during its pirouette while on the forklift. My guess is that the box is already empty before the forklift picks it up.

The balloons are not there for no reason. Disguising a winch cable perhaps?

The guy on the mezzanine (piano player?) at the end is pretty unimpressed, inferring he was at the proper vantage point to see all.

But this is all still just conjecture, of course.