This one definitely looks like a space jockey head piece or something very similar.
All the elements are there in the raw NASA image, I have not added anything apart from enhancement to expose details, and colorization, other than that I have added nothing.
The second and third video show another interesting anomaly found by the rover, which looks like a little Martian.
Whatever it is it looks humanoid, reminds me of the Atacama Alien, about the same size too, this one is around 6 inches.
Link original images: