In the original orientation of the image I was stumped
by the elongated shadow near the bottom of the above enhancement.
I could not find the source of the shadow given the sunlight angle,
which is coming from the above right.
After rotating the image attempting to find an answer
to the mystery, I discovered something startling. The image was
posted upside down on the JPL website! The convincing evidence
is written in the sand. Notice the sand in the first original
image...it is clinging to the tops of the rocks. In the rotated
version, the sand is laying correctly on the ledges of the rock.