Symbolism, Imagery, Allegory
The Best Part of Waking Up (From a Coma)
Mia's family likes coffee, and the blacker the better. She decides that this is the cool way to drink coffee. According to her, there are "people who drank plain coffee and people who drank gussied-up caffeine drinks like the mint-chip lattes Kim was so fond of" (10.41).
That's a burn, Kim.
Maybe one of the reasons Mia feels she can leave Kim behind is that Kim just isn't cool enough.
In any case, this is the kind of black-and-white logic Mia applies to coolness. You're either cool or you aren't, but the criteria are kind of random. Maybe that's one of the reasons why Mia is so confused about her identity—she hasn't learned to think outside of these categories.