In Sonja (Hannah John-Kamen)'s video game collection, the game Dark Souls II (2014) can be seen. The actress who plays Sonja, Hannah John-Kamen, was a voice actor for Dark Souls II, in which she played the character Sweet Shalquoir.
The grand estate where the game company is located is Englefield House in Berkshire, England. This same estate is used in several other films and TV series, such as X-Men: First Class (2011) in which it was used as Xavier's School for Gifted Youngsters (a.k.a. the X-Mansion).
Several references are made to the Indiana Jones franchise. Sonja (Hannah John-Kamen) compares Cooper (Wyatt Russell) to Indiana Jones, the bar where they meet is named The Raven (as is Marion's bar in Raiders of the Lost Ark (1981)), and Cooper mimics ripping the heart from the figure in the house while shouting "Kali Ma," mimicking Mola Ram's character in Indiana Jones and the Temple of Doom (1984).
At one point, Cooper (Wyatt Russell) is seen reading The Raven by Edgar Allan Poe, who was famous for writing in unreliable narrative, the same way this episode was written.
One of the symbols on the AR system is also featured in Black Mirror: Bandersnatch