IDEA: shadows and intangible imagery

I'm in the preliminary stages of a new piece that is going to cast significant shadows if installed on a wall. I've been contemplating how best to make use of the shadows, and ran across some images of Kumi Yamashita's work. Now I'm fascinated by the idea of incorporating an intangible image, dependent entirely on the correct angle of light or viewer perspective.

This Yamashita piece particularly caught my attention because it looks similar in scale and installation to mine. Brainstorming...