This came from a segment where Roxie is exploring her surroundings and, curious to explore what music is all about, visits a record store. The man explains to the bizarrely green, no-nose lady that music is a form of expression. This is definitely an alien concept to Roxie, since Irken culture has been and always will be about conquering and even now the eternal quest for universal supremacy has left no room for free expression. This is right before she finds a way to "disconnect" herself, so she doesn't think much of the visit lest the Control Brain suspect something.
This was earlier in the year while I was initially developing the character. If I find the time, I will develop her story further especially since it involves the time on Earth before Zim came along.
Invader Zim © 2001-03 Nickelodeon (Created by Jhonen Vasquez)