Interesting? I have seen some funny lights in the sky doing things that one doesn't see everyday. I can say that the angle from the vehicle rules out a natural optical illusion. However one can use a small mirror on a digital camera and get the same illusion.

This is one of those things that a person would need to be present for the description to be considered, because there are a lot of ways to create such illusions. Anyone for instance can paste an object in the sky and make it appear to be hovering using photo editing.