Agreed with others that it's probably fake, but there I disagree that it's impossible. One of the slightly counter-intuitive things you learn when becoming a pilot is that you take off into the wind rather than with a tailwind. The wings don't care what your ground speed is when creating lift, they care about your airspeed. Given a big enough "kite" and a nice headwind and of course you can do this. Kitesurfers, kiteboarders, and hangliders do this all the time. The flapping may or may not assist, but it's certainly not doing the brunt of the work.