I went back to grab a better look and it was a magicians slight of hand ;-)

No new tricks here :-) It was early morning...
Glass Windows Streetside

There is a projector screen that is like a sticker on the inside of the glass window.
There is a projector feeding the image from behind it.

The effect however is very clean......seamless. Not like your typical plasma display on the window. No bezels, etc. The video just appears on the window in a nice square setup...