The concept of shadow, of course, is easily understood. But then again, how often do we see (or notice) a double shadow in natural light? Natural, that is, meaning not a staged effect.
A bit hard to see, but two shadows from the electrical cord against the wall (marked by arrows).
The dual light source is from a window directly to the right, and another window in the opposite wall.
Simple stuff. I just love spotting something I understand from book larnin’ to be true, but that reveals itself in a natural occurrence as proof.
An interesting note: When I went to take a picture, I realized that the flash would either throw a third light source into the scene, or obliterate the shadows of the other two. Covering the flash and zooming in did the least damage.
The Lost Children: A Charity Anthology