Photography

Photography is a strong tool, a propaganda device, and a weapon for the defense of the environment... Photographs are believed more than words; thus they can be used persuasively to show people who have never taken the trouble to look what is there. They can point out beauties and relationships not previously believed or suspect to exist.

The step from the age of Typographic Man to the age of Graphic Man was taken with the invention of photography.

The image (shadow) being inverted depends on there being an aperture at the cross-over and the image (shadow) being distant. The explanation lies in the aperture.
The image (shadow): The light reaches the person shining like an arrow. The lowest [light] that reaches the person is the highest [in the image] and the highest [light] that reaches the person is the lowest [in the image]. The feet conceal the lowest light and therefore become the image (shadow) at the top. The head conceals the highest light and therefore becomes the image (shadow) at the bottom.