Both are great postures and most likely an adjustment to ball location IMO. You can start over the rear hip and if you have to adjust forward but you will never be able to start in front of the hip and adjust back.
The one on the right was when she was struggling badly a while back - Ks, pop-ups, weak ground balls. We were seeing this head-hip relationship consistently. When you got her back on track with working over/behind the hip, she quickly got back to hitting like Maddie. A big part of it was how her torso position affected her barrel path, but it also affected her quickness and adjustability. Being ahead of the hip might work for some hitters. Maddie is not one of them. This has been proven with her multiple times.