The Sankara Stones, the Macguffin from Indiana Jones and the Temple of Doom (1984) can be seen in Luthen's store. This is a call to the Indiana Jones movies also in the way they always had a Star Wars reference hidden throughout the films.
Fondor is briefly mentioned in this episode. Fondor is home to the Imperial shipyards that produce the Empire's Star Destroyers and plays a large role in Legends material.
The proverb "the axe forgets but the tree remembers" is Zimbabwean from the Shona tribe. It means that a person who harms another or borrows from someone will often forget, but the person who is harmed or borrowed from will always remember.
The "navigational tool" that Karis shows Cassian is clearly a repurposed Polaroid SX-70 camera.
In the back of Luthen's shop two objects on an upper shelf very closely resemble Jedi and Sith holocrons like the ones seen in Star Wars: The Old Republic (2011), Star Wars: The Clone Wars (2008) and Star Wars: Rebels (2014).