I studied this quite extensively. The lander slid (or possibly bounced) to the left and then rotated clockwise in the instant the footpads made contact. The flat part you see is the part that has been mashed by the footpad. In this picture the footpad has slid probably 18-24 inches from lower right to upper left. And then it has moved a few inches in the direction from upper right to lower left. This pushed the contact probe aft in the trench it had dug, leading to the building up of regolith on the near side of that trench.
We know the regolith responds cohesively to compaction. Then in this case, compacted regolith is strained in the direction perpendicular to the compaction. This will tend to fracture the compacted layer. I believe the feature in question is a web of cracks in the layer compacted by the previous passage of the footpad over it.
I studied the soil mechanics and final disposition of all three contact probes and the three photographed footpads in order to form this opinion.
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