It's easier to see on back styles that are not wings. Shoulders are uneven in one direction, waist is uneven in the opposite direction. It looks like a chiropractic nightmare.
If you look at the placement of the wings, they kinda slip out of position when you 'hover' Personally don't have a problem with the waist position, that's due, partially, to the raised knee (which has switched side since 2011)
honestly the only wing style i haven't seen this effect are the wings of sin, and it's noticeably less on the small bird wings.