I really like the illusion of light in this one, both in the differences in shading on the different sides of Buzz Aldrin's body, and in the reflection of the helmet. Apparently, the reflection in the original photograph shows the LEM and the photographer, Neil Armstrong.
Dave follows up this foray into space with another space-themed mosaic, an "adaptation in LEGO of the "Earthrise" photo taken by astronaut William Anders during the Apollo 8 mission, the first manned voyage to orbit the Moon."
You can read more about the original photograph and get a close-up shot of this mosaic here. Be sure to check out the different colors it uses.