APOLLO 17 PYRAMID ON THE MOON

the swamp geese were a lot more rectilinear in those days.

Why not follow your own link?

These are the shots taken just before:
[link to www.hq.nasa.gov]
[link to www.hq.nasa.gov]
[link to www.hq.nasa.gov]
[link to www.hq.nasa.gov]

It's the floor of the rover.
Harrison might have accidentally pressed the camera button during the ride.
Or, since these are the last frames of the magazine, he just wanted to get to the end so he could load a new one.
Frames at the beginning and the end are the most likely to be sun struck.

Each and every time a hoaxie claims that "all the Apollo pictures are perfectly framed and focused" they aren't just wrong, but since the claim implies they've seen them all, they are lying.