Blue Quadrangle UFO Filmed Over Volvic, France (Video)

A strange, blue, quadrangle-shaped UFO was filmed over Volvic, France, expanding before zooming out of view. What is it?

The unidentified flying object was caught looking out a window and, at first, seems to be a reflection. But soon the object begins to expand into quadrants and begin dancing through the sky.

Evolving from a pair of blue lights, they eventually split and form a rectangular shape before dipping out of frame and out of view.

There is not much commentary on the YouTube video, only to say it was filmed in Volvic, France and that the user is not quite ready to say for sure it's a UFO. But, it's obvious that the witness has no explanation of what the OVNI is and is looking to the audience for answers.

So what is it?

Here's the video: