This image represents the very first time we have been able to acquire a visual on any kind of probe landing on the surface of another moon/planet. What is (clearly) seen here is the Mars Phoenix lander in the parachute phase of its descent. You can even make out the shape of the thin threads that hold Phoenix tethered to its chute.
Normally a visit to another world is a solitary experience, but as many as 3 other probes already in orbit around Mars (Mars Reconnaissance, Mars Express and Mars Odyssey) were timed out to be in the general overhead vicinity of the Phoenix landing. It just so happens that one of them, Mars Recon, has very sharp eyes.