I've rotated the image in 3 different programs, (as well as registax) & they all gave the same effect for some reason. (image above rotated using pic. publisher)

Would I be correct in saying the more images stacked in the final version, the bigger the degredation/elongation of it upon rotation?
I came to that conclusion during the mars madness just recently. 1 out of my many mars images refused to rotate correctly & it just happened to be the image with over 800 frames stacked..