That truly is a mystery.
Maybe it wasn't a shadow, but a spray painted image?
Good eye. Most people would never see such detail.
I'm guessing that it's on the roof Marianne, well spotted!
A real mystery!
It has to be too far back on the roof to be directly seen from the street.
Is it possible the image was printed onto the wall rather than a shadow?
Wonderful observation. Wonderful magic!
A strange shadow.. :)
Ah, a good mystery to solve!