When trying to think up Halloween costumes for Julien and Zoya, they mention 'all of the Olsens', aka the twin sisters, Mary-Kate Olsen and Ashley Olsen and their younger sister, Elizabeth Olsen. Luke Kirby (Davis Calloway but doesn't appear in this episode) played a one-night-stand of Elizabeth's character in the TV show, Sorry for Your Loss (2018). They played Tripp and Leigh Shaw respectively. The episode in question is, Welcome to Palm Springs (2018).
When trying to think up Halloween costumes for Julien and Zoya, they mention Anna and Elsa, the two sisters from the movies, Frozen (2013) and Frozen II (2019). Kristen Bell, who voices Gossip Girl, is the voice of Anna in the movies.