What about these images:
[ATTACH]40512[/ATTACH] [ATTACH]40514[/ATTACH]
...compared with this image:
[ATTACH]40513[/ATTACH]
All 3 images have the stripe in the same position, but in the first 2 images you can clearly see that the cape's end extends beyond the outer shoulder stud and goes to the jetpack's upper hook. And in that image from the back, the cape is in the same position (it never changed its attachment point), but in some images it is wrapped behind the left shoulder/arm, while in some images covers the whole arm, this is why the stripe looks like it is in different positions.
And finally, a clear(er) shot of the back with the cape going straight to the jetpack's hook:
[ATTACH]40515[/ATTACH]
The cape never changes its position.
