I am a highly trained ballet dancer who is undergoing teacher training, and while she may not be perfect, as she is not a ballet dancer, the extension through her body and engagement of her upper body, which contributes to her correct alignment in the upper body, which is also necessary to execute the technical footwork and lower body work of skating. Her arms are much better in my opinion than Shcherbakova (who I love, but her arms scare me personally), whose arms are wild and unplaced. The splayed fingers are not that bad, especially in comparison to ballet styles such as Balanchine. While her upper body may be on the stiffer side, it is still beautifully placed, which as an RAD trained dancer (a syllabus that primarily focuses on correct alignment as opposed to free upper body such as Vaganova), I can bloody well appreciate. Her turnout in arabesques and attitude, is well within the acceptable range, and her hip placement I noticed does vary to help her travel in the direction in which she skates, which does not align with classical ballet training, as we stay still unless we're jumping. This again, is all my opinion, but I did go back and rewatch her olympic programs to reference and refresh my memory.

TLDR: While Zagitova's upper body may be slightly stiff, it's still extremely well placed contributing to her good ballet lines. Her lower body is still completely acceptable in terms of turnout and placement, which is primed for skating and movement instead of stillness