You're looking at the breathtaking work of Kumi Yamashita. The New York artist has made a name for herself crafting human figures out of the most unconventional media, including nails and sewing thread, denim, and — in the case of the sculpture up top — light and shadow.
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).
You'll find many more examples of Yamashita's work on her website.
[Spotted on boingboing]