The hovering illusion is because the airplane doesn't "know" its speed across the ground, the only thing that matters aerodynamically is its speed through the air. With a strong enough headwind and a slow enough airspeed (in this case, frighteningly close to a stall), the plane would appear to not be moving from the perspective of someone on the ground.

A similar stunt in an A320 at an airshow in 1988 killed three and wounded 50 (Air France Flight 296)