Look at the zoom on this page. You can see the heat shield still attached, the full parachute, even the tether lines.
BA says it best:
Think on this, and think on it carefully: you are seeing a manmade object falling gracefully and with intent to the surface of an alien world, as seen by another manmade object already circling that world, both of them acting robotically, and both of them hundreds of million of kilometers away.Now _that's_ engineering.
Update: APOD for 30 May has Phoenix's descent in a wider context.
I still think this is one of the most significant engineering photographs ever taken.
