Tiff and Loy

thanks both.
Good eye Novocaine. The cubes are shadows. See the solid-looking one on the left? That's a piece of the original artwork. The artwork comprises a few lightweight, free-rotating, suspended 1D prisms that should be placed near a light source to allow them to project shadows of various focus and size.
My intention when taking the photo was to ensure they were present in the frame. Their shadows are so hazy and so subtle, i couldn't risk exposing the image to any more light.