My goal was to pass to the outside (side walk) the ambience lived in the gallery.
To do so, I put a mirror on the inside of the window, and through face detection, I had a photograph of each visitor. After that this photograph was part of a mural that was being projected on the outer wall opposite of the window. This mural was animated with the sound of the environment in the gallery. It was all realtime and worked as a magic mirror of the experience being lived by the visitors of the gallery.
More info: http://bit.ly/eZLlzU