Exposures made with the entire vehicle in view, by what again? A magically levitating camera off board from the vehicle?
And yes, I worked at Marshall Space Flight Center and they absolutely do air brush some photos. I've eaten lunch with people from that department.
The arm has been removed from the image since the 83 images were stitched together, they most likely didn't want it to block the view. There have been other images put out that have removed the arm from the view the past years as well. The arm is attached to the cone looking piece next to the wheel.
makes sense. but rendering the image as if it weren't there makes you wonder what other stuff is fake.