Bristi Dey
Orange headphones
One of the film's subtle pop culture nods comes through Supergirl's signature orange headphones, which she wears for much of the movie like most of the cool girls of this generation. However, if you look close, it mirrors Marvel's Star-Lord, whose iconic orange Walkman.
Pop culture nod
The movie features a few pop culture references but you really need to notice them. During a barfight she orders the band to keep playing the music which somewhat resembles the Titanic scene where music goes on amidst the chaos. And then there's the reference from SpongeBob. She calls one of the aliens Squidward, the lovely squid from the cartoon.
Sun theory
One interesting detail in the movie is how different-coloured suns affect Supergirl's powers. A Red Sun diminishes her powers and a Yellow Sun gives her powers back and meanwhile, a Green Sun weakens her so much that she can barely move. This is a clear ode to the effects of Kryptonite which not just affects the newest Supergirl but also a few in the DC universe.
Argo city
The dear home of both Superman and Supergirl looks something truly magical. But did you notice the resemblance? The city feels heavily inspired by the artwork that Bilquis Everly created for the Woman of Tomorrow comics and some moments from the movie looks as if it has been taken directly from the pages
Streaky the Supercat
The cute little feline has been a part of the Superman family since 1960. In this film, it appears briefly, and thus acts as a hidden nod to longtime DC fans who are the only once who can understand the animal's reference. The cat appears to be the funny character in the movie.