It doesn’t matter. Look what happens when you expand the idea: it becomes art.
“I sculpt shadow with light or sometimes light with shadow, but both function in essentially the same manner. I take objects and carve and place them in relation to a single light source. The complete artwork is therefore comprised of both the material (the solid objects) and the immaterial (the light or shadow).”
The artist is Kumi Yamashita.
Go here to see a gallery of her work on the Demilked website.
Or here to her website.