Several cast members were on other Shondaland productions:
Katie Lowes (Rachel), Jeff Perry (Lou). Kate Burton (Nora Radford), and Joshua Malina (Henrick Knight) were on Scandal.
Marika Dominczyk (Talia Mallay) was on Grey's Anatomy.
Anna Deavere Smith (Maud) was on For The People.
Arian Moayed has appeared many times on Succession (2018) many times alongside Dagmara Dominczyk, real-life sister of Marika Dominczyk who plays Talia Mallay in this episode.
Talia Mallay (played by Marika Dominczyk) is a creation of the show's writing team, and is likely based on several socialites and entrepreneurs tricked by the real Anna Delvey. One major inspiration for the character may be hotel empresaria Jayma Cardosa.
The fine art photograph that Anna and Talia discuss (and which Talia purchases) is "Untitled Film Still #17" by Cindy Sherman.