I know that I've seen this video before, and I could've sworn I saw it here. Oh well. It's funny.
Does anybody know what this behavior actually is? Do they think the phone is a small animal that they are about to kill?
The behavior is sound localization. Owls have particularly unique ears in that they are asymmetrical; sounds from above are louder in the right ear, sounds from below are louder in the left.
Animals can make strange movements when they are trying to find the origin of sound (sound localization). It's the reason dogs tilt their heads back and forth curiously when you talk to them: You are making a noise that is confusing to them.
So these owls aren't "dancing." They are trying to figure out where the sound is coming from.