There is a deleted scene in this episode where Vala and Faora visit Clark in his loft to thank him. During the scene, Clark is seen wearing his plain red t-shirt for the first time since Season Eight's "Eternal".
In the newspaper article that Lois reads about romantic getaways, the byline says that the author is Joanne Totten. Joanne Totten was formerly an art assistant for "Smallville".
After Chloe Sullivan tells Oliver and Lois about all the surveillance she's placed on the Kandorian army members, Oliver refers to "1984: The Sullivan Edition." 1984 is a novel that has a theme of pervasive government surveillance.
Faora mentions the Argo Valley on Krypton. This is probably a reference to Argo City, the home of Kara Zor-El/Supergirl in the comics and in Supergirl.
Chisholm's skull cut and pierced with Kryptonite needles is a homage to Pinhead, the main antagonist in the Hellraiser film series.