Whole body is turned 45 degrees toward the camera, you can see it on legs, that changes all angles and deflections.
Yes, that makes it difficult to really see what's happening.
Down, 3rd corner of the outside squares, about the center of the turn.
Up, 4th corner of the inside squares, about the center of the turn.
Turn from inverted, second half of wingover, initiating the turn, in this case if we were perpendicular to the lines the wrist angle would be greater.
Both shots with lines near perpendicular to the line of sight og the camera. The hand twist may give the illusion, but if you look at the rotation of the wrist there a very noticable difference. However, mimicking these movements with my are and wrist, it appears this is an anatomical limitation. Makes me think about a biased handle again.
Looking at this again, the camera height is wrong to for really observing the geometry of the lines and hand,it should be at the pilot's shoulder level.
Tried to get a snip of level upright hand position but they're edited out and only the maneuvers are there.
Only my observations, I have a pretty good eye for shapes and angles.