So there's technically three types of shadow rounds: shadow and then two types of what's called reverse shadows. There are shadows where an interviewer in-training shadows a trained interviewer—this counts. RS rounds are where an experienced interviewer observes an interviewer in-training conduct an interview. For someone training, this could either (1) be their first time conducting something for Meta OR (2) it's their last time before the interviewer observing gives them the green light to go solo. For the RS rounds, (1) isn't counted. However, some pipelines count the feedback from (2) since the interviewer in-training is essentially done with the training program and can discuss/review their feedback with the observer. Usually the type of shadow isn't really told to candidates, so it's hard to make a blanket statement about whether they all count or not.