we really should be using the versions in the pds as these do not generally have any pure black areas in them. The versions at http://marsrovers.jpl.nasa.gov/gallery/ often have blacked-out areas because of the contrast and other modifications they are subjected to. see the pure black areas where no extra detail is available.
I examined your Panorama at a glimpse and found this is not the only anomaly present.
There's also another object hanging out and next to it one hovering. (Just one amongst several)
And here is a super giant Rover Track. I Assume it must be supergiant because it is located on the upper right side of the image near the horizaon, and spans a whole mountain.
Pretty cool, I found a youtube video awhile back where someone was comparing some official nasa photo's of mars to some pictures of desert landscape of arizona. And it was nearly 100% dead on. Ill do some searching for it and post is its pretty bizzare. This is pretty cool too, thanks for posting it.
This is one I'd really like to check the left right views:
These are the links he gives, which unfortunately, are links to over a thousand images, so I don't know the exact source to verify it - or try and find the sol # to check for other views.: