Dancing windows

If you look outside on the right kind of day you can see something unusual from our kitchen.  I like to call them dancing windows, and I've only seen them a handful of times. The first time I saw them on the side of the building across the street, and it took me a while to figure out what it was.  

The sun has to be in the perfect position to reflect the light onto the neighboring building, and the wind has to be blowing strong enough to move the windows, sustain the movement, then die down for a bit so the window will close again, AND the wind has to be blowing from the right direction.

I just caught a bit of footage on this day.  There have been days when it's been much breezier and the reflections from the windows are going all over the place. I love those days.