How does this work?

Very clever but it's not real. It's simply an extremely clever animation.

The thing that appears to give it away to me is the, supposed, porthole/window in the background. The scene through the porthole is of the moon and the moon moves across the porthole as the 'camera' moves around. So the porthole can't be a picture on the wall.

As a proper porthole not only is the moon shown to be too close, but it changes phase during the music. Therefore the whole thing is a computer generated effect.

Unless, of course, the aliens have arrived!

 

Very clever - its probably only a matter of time before someone manages to actually make a computer controlled instrument similar to the one in the animation.