I think it is throughout the tranining
Yeah + it didn't have to have physical abuse during the training (except for that necklace scene) for it to be hella traumatic for Shuri. She was being politically groomed by the man who always seemed to look at people as if he was gauging their life's worth based on their "usefulness" (as seen from the knight who was Abington's sister I think) and from what we've seen so far from the chapters, she has always intellectualized and rationalized her trauma because the man was "kind" to her and to other people. That kind of trauma response wouldn't just stem from one incident. She definitely suffered from some physical and psychological abuse, whether it was Johannes' intention or not.
Ok so is the domestic violence implied just during the necklace scene or throughout Shulie’s marchioness training?