They just want you to believe it's rocks.
I was looking to see if there were any arrowheads and other Indian artifacts laying in that picture.
In the center of the photo, I suspect they perceive the object to look like a canteen cup with the opening facing you (shadow), with a lid and handle half way open downwards.
The other photo with the “fork” resting atop the bowl, appears to look like a spare tire wheel cover off an earlier model Thunderbird, and the fork looks like a Spanner wrench of some sort.
The combination of the semicircular shell, with the other anomalous wrench-like artifact atop it, does appear to be intelligently manufactured.