One more pesky question about the Mars indentation

Will someone please explain to me how a "rock" can show depth, AND have another smaller rock inside of it? I mean you can see shadows on the right side of the wall of the "imprint"
I'm not looking for martians, I would just like to know how it possibly could have been made, and how it got there. Sorry is this is OBVIOUS to certain people but I still see depth in the thing.
Thanks in advance

Its the rock and shadow lining up.

(From the previous image in the series


Heres the shadow from the rover:


And heres the rock:


No footprint or any other fanciful meaning to this.

Well, though I'm not sure how an indentation of that shape could occour, the rock being inside of it could have happened simply through the winds on Mars, which can get pretty fast. If it was blowing a small pebble that pebble could have rolled over that rock and fell into the hole.

And an idea of how the hole was formed has just come to me! (Yeah, but now my brain hurts....) It may have been cracked durring a storm when another rock slammed into it, and the crack kept expanding through erosion from all of the dust and wind.