[hide] If you compare number 1 to number 2, the differences are background and colour of the lines, that makes two differences. If you compare number 3 to number 4, the differences are shape of the thing around the pearl and the colour of the pearl, also two differences. But number five. If you compare it to another, you only get one difference. To number 1: Colour of the cube. To number 2: Background. To number 3: The shape of the thing around the pearl. To number 4: The colour of the pearl. Now you got two differences with the others, but only one with number 5. So number five is most unique because it's the less unique. ;D[/hide]