I state, that represented on the drawing of a prison jumpsuit, there is in fact a series of crude strings of which the pattern of full lines and striped lines does distinctly resemble attempts at drawing 3 dimensional rectangles on a 2 dimensional surface.
Any other statements, that these are actual hypercubes, regular cubes or squares, are clear falsehoods as evidenced by the shear lack of any 90 degree corners or straight lines in general.