Hangover
Charlie has been drinking too many vodka lemonades to the point that simply standing up is a challenge. He can sense a friend is talking to him," snapping me out of my daze, but it’s still like I’ve got cotton wool in my ears and nothing that’s happening is actually happening." This simile comparing the cessation of the senses working at optimum efficiency is an accurate description of the consequences of drinking too much. After the fun comes the payment and it is never a fun toll to pay.
Pop Culture
"He genuinely does think he belongs in a Wes Anderson film." This description of a character named Tao is a difficult metaphor to explain to anyone unfamiliar with the reference. Wes Anderson is a film director with one of the most immediately recognizable styles in Hollywood history. For those who get the reference, this metaphor for self-conscious self-awareness of one's self-identity makes perfect sense.
Food
Food references are fertile material for the comparative structure of the simile. "Mum walks in at around 1pm to ask if I want lunch, but stops when she sees me wrapped up like a burrito in my duvet." The increased familiarity with burritos around the world makes this imager immediately relatable. It is the addition of the specificity of the item—a duvet—which helps to give it an idiosyncratic twist which offers insight into Nick.
The Photographs
A series of actually developed pictures Nick and Charlie have taken of themselves and each other becomes central to the narrative. But as he is looking at them at one, Charlie realizes that they're "all tinged purple and blue and orange, muted colors, a little blurry, like polaroids at an art-school exhibition." The suggestion is that the pictures are works of aesthetic intent. But neither Charlie nor Nick consider themselves photographers. The dissonance between the reality of the photography and the suggestion within the simile stimulates a deeper understanding of their relationship to Charlie.
Hyperbole
For the most part, the use of metaphor and simile in this story avoids hyperbole. Not completely, however. "Nick touches me like he’s scared that any minute I could disintegrate forever." The overstatement here is appropriate to the situation. It is the sort of thing that is perfectly at home in a teen romance.