It overlays the map over the satellite images but its really accurate. I saw a guy do a proof of concept on this using the maps API awule back but his was not even close to this clean. This is really amazing. They have either really accurate map data or they are using some sort of road finding algorithms to tweak their map data to match the satellite images or vice versa.
BTW... that link shows Fuzion where we have the SD GTGs right in the middle. The pink roof is the strip club across the street.