He's showing how stable it can be with unbalanced props and load, and the other things, it's an "extreme test"
The motors adjust to keep it stable, very well too, it's similar when you fly in high wind side on with GPS / VPS keeping it in place hovering.
Standard stuff like people throwing new iPhones that jsut came out under a rock or in a blender to "see how it holds"... stupid, but tends to get shared tons, gets lots of views and thus brings a bunch of $.
..And to think the manual (pg 7) says "All arms and propellers must be unfolded before powering on the aircraft, or it may affect Self Diagnostic Testing.
Thanks for sharing.