This design is obviously a combination of Albert Einstein's face and the style work of artist MC Escher. Escher did some designs involving faces, 'peeled' so to speak in this style.
Albert Einstein's famous relativity equation of course is E=MCsquared, so combining this play on words worked well.
I originally subbed this 3 color design on a khaki colored shirt, but I think threadless did well to change it to the color schemes for the shirts they chose.