Very informative - and cautionary for people trying to interpret video images on YouTube, as even trained pilots can be fooled by things like parallax. In fact, I'm reminded by this of the parallax effect one often sees when driving past an airport. Landing aircraft can seem to be flying backwards (!) , since they are being observed relative to a background - of trees or buildings - that is a lot further away than the plane. The motion of the observer's vehicle is responsible for the apparently anomalous motion of the place.