For clarification, the animation I posted in Reply 6 was not meant to show that the thing moved. (In fact, it did not move). The purpose was to allow you to see the difference between the two png's I posted, when the image was taken from extremely different locations. Clearly, this is a single object and not an illusion caused by rock position. If there is any question in your mind about that, take a look at the two png images separately. One is taken when the object is at the extreme left side of the rover, and the other is taken when the object is at the extreme right side of the rover.
This animation, on the other hand, is for your amusement:
