[incrudible]

You would be surprised what can be achieved with bit of nylon string and an appropriate camera setup. If this is a most groundbreaking discovery, why waste all that screen resolution on the backdrop?

[wesleychen]

I think because the minimum focus distance for most phone cameras is around 8 inches so they have to film kind of far away or else it will go blurry.

[anonymousiam]

I believe the backdrop is there to show ambient conditions.