Yeah - it looks like the rover rolled over it broke the rock. The "smooth" surfaces could also be ice (though it seems too smooth for ice) that did not thaw in the shade of the stone. Next mars summer it would be interesting to see if the ice melted and the "pool" evaporated (dessicated?).
Waiting for some polar rovers - it's a sure there's some kind of bugs in that ice.
The Russians were going to drill that anarctic lake - what ever's under the ice there is ancient for sure - but maybe they're saving it to test prototypes to get under the ice on Europa. Weadership should buy a lot more excitement from NASA.
Willey Ley (or Ney?) and Tom Corbet Space Cadet!:-)