"do you listen to neon trees?" is code for "are you pansexual?" or from the "i" point of view means "i am pansexual"
person 1: hey, do you listen to girl in read?
person 2: no, but i listen to neon trees.
p1: oh nice! are you clarifying your sexuality in any way? if so, i listen to sweater weather.
p2: yes lmao, i'm pan :)