The weight of the lunar module, on top of the command and service module, was the main reason why the Saturn V rockets that shot Apollo astronauts into space needed to be the tallest, heaviest and most powerful ever flown, a record they still hold.
On the back, the camera still peeks out of the top-left, but the module is considerably larger now and, where it was inset on the fourth-gen iPod touch, it now protrudes slightly -- just over 0.6mm, by our measurements.