A cube is made of 6 2D squares, the sides. A tesseract is made of 6 3D cubes, the sides... they're distorted to make perspective like a 2D square is... you know, look at the logo for the new Minecraft.exe... You can see that each side has been distorted to look like rotated 3D objects? http://www.youtube.com/watch?v=AzL091mZQ-E