Ralph suggests "Soundwave" as a nickname for Izzy Bowin, before Cisco shoots it down as it's already the name of a Transformer. In fact, there are a number of Transformers with this name.
One of Izzy's updates mentions a "starfish situation" in Blue Valley, a callback to Therefore I Am (2017), in which Wally mentions having battled a "starfish from outer space", a reference to Starro.
Ralph says "Killer robots come out of this elevator." This is a reference to Metallo coming out of the elevator and shooting Supergirl in Crisis on Earth-X, Part 4 (2017), Legends of Tomorrow episode 3x8.
The song sung by Izzy Bowin at the beginning of the episode is the country single "Somethin' Bad" by Miranda Lambert and Carrie Underwood.
This is the second episode of The Flash (2014) in which Jesse L. Martin (Joe West) does not appear. The first was Crisis on Earth-X, Part 3 (2017).