The episode's world premiere public screening was at the BFI Southbank in London on 19th June 2018, five days before it aired in the US. The screening was followed by a Q&A with the episode's writers (and series co-creators) Jonathan Nolan and Lisa Joy.
The mansion that Dolores and Bernard are in during the first of Delos's memories is the same building used in True Blood as Queen Sophie Anne's home. Queen Sophie Anne and Dolores are both played by Evan Rachel Wood. The name of the estate that houses this building is known as "La Villa Contenta" and this building is actually the pool house on the property.
When Dolores and Bernard visit the library within the Forge's mainframe, you can briefly spot the same Armillary-Sphere-type lighting device that appears in the opening credit sequence of HBO's other hit series, Game of Thrones. In the sixth season finale of GoT this device is actually implemented in the show itself- also as a lighting device, in the Great Library of Oldtown. Both Westworld showrunners Jonathan Nolan and Lisa Joy-Nolan said they are big fans of Game of Thrones.
near the end of the episode it's mentioned that they're to meet Karl Strand on the beach. The surname Strand means "beach" or "shore" in German, Danish, and Swedish. Gustaf Skarsgård, who plays Karl Strand, is Swedish.