Maybe his just showing you everytime he solves a side. There are many outcomes to this picture. And also showing us he had some down time to solve that much! But hasnt had the time for the other sides!
This photomontage is effective because the pronounced highlights and shadows gives the image a lot of contrast and more visually interesting. The overly pink flesh color against the smoggy background gives the image a dreamlike look. The colors all blend nicely together as well and makes a surreal image appear realistic.