In a 2021 interview, Laura Vandervoort revealed that she had heard (after the show ended) that this episode was done as a test pilot for a possible Supergirl spin-off.
When Kara is wearing her red and blue costume, it resembles the Matrix Supergirl costume from the comics.
Kara left Smallville in order to find Kandor, and was last seen, in Season Eight's "Bloodline". She states that she did not find any survivors and that she and Clark are the last members of the house of El.
Clark actually flies in this episode for a brief instant but loses concentration and falls back to Earth.
Lois comes up with several different monikers for Kara including Power Girl, which is the alias of another DC super-heroine most commonly associated with the JSA, being their first new member and first female chairperson. Power Girl (Kara Zor-L aka Karen Starr) is the cousin of the late Superman of Earth-Two (who viewed her, as his daughter) and their version of Supergirl. She ended up on Earth-1 after Infinite Crisis in the comics. It's also an alias used in an imaginary story (told in Superman #125), by Lois Lane herself. Furthermore, Allison Mack voiced Power Girl, in the animated Superman/Batman: Public Enemies movie. Lois also calls Kara on two occasions "Übergirl" which can be translated to mean "Supergirl".