Second live action appearance of Wullf Yularen. The first was the ISB officer in the conference room on the Death Star in Star Wars: Episode IV - A New Hope (1977) as Colonel Yularen. This character was unidentified in the film, but received a name in the 1995 customizable card game by Decipher.
A few of the items on display in the front of Luthen's shop when he is speaking to Mon Mothma include a mask from a Jedi Temple Guardsman as seen in Star Wars: The Clone Wars (2008), a Gungan personal energy shield from Star Wars: Episode I - The Phantom Menace (1999), and a Kel Dorian Rebreather.
The tune that Andor knocks on Bix's wall is "Shave and a Haircut," a well known musical riff that is thought to have originated in late 19th century America. It marks the first inclusion of a real world piece of popular music in the Star Wars universe.
This is the first time there is a significant time jump between events in the series, when Cassian leaves Ferrix and is next seen on the tourist planet of Niamos. Until now, the action of the first seven episodes has taken place during a few days, from when Cassian kills the guards through the heist on Aldhani and Cassian's return to Ferrix.
On her way to meet Vel, Kleya passes an Aurebesh sign which first reads "Tasty Peezos" and then changes to "carry your chain code - from the ISB".