When Violet is leaving the church of the final grandparent's funeral in England she has a haircut with a fringe (which she has whilst dating Winton). When she returns to the USA with Tom the fringe is gone and remains gone for the rest of the movie.
Throughout the film, Violet and her colleagues refer to people taking part in their psychology experiments as "subjects". This term is no longer used in psychology (and has not been used for decades) as it is thought to be disrespectful and has unethical, dehumanising connotations. Rather, today psychologists use the term "participant" to refer to people who take part in an experiment.