What you see there is a tesseract. In case you're not quite sure what that is (I wasn't), the short definition is "the four-dimensional analogue of a cube." Or, to be more specific (for those of you as nerdy as I):
Four-dimensional hypercube; its vertices are (+/-1, +/-1, +/-1, +/-1). It is a polychoron formed from eight equal cube cells that are perpendicular to each other at their faces. It is the tetraspace analog to the square in planespace and the cube in realmspace.