Emma's line about her being "the bitch with the time machine" is reminiscent of another time-travelling villain. Missy is a recurring villain in Doctor Who (2005), and in The Witch's Familiar (2015) she let it be known that "the bitch is back!" Incidentally, Missy always wears early 1900s clothing (Edwardian England), which is not too far off from the outfit that Emma wears here.