poop: an abbreviation for people observing other people. these "poop"s include popularity hungry people, who watch the "popular" crowd's mood and then copy them, in an effort to be accepted by them. Another example of a poop is a scientist who studies human behavor, and therefor, watches people. Also, it could be a girl or boy watching a girl or boy that they have a crush on. Or anyone else that has characteristics of types of people listed above.
Scientist: (says to random passing guy) hm... look how that man chews his sandwich so slowely, how interesting!
random passing guy: dude, your such a poop
Popularity hungry girl: oohh look how cute Janie's("popular" girl) new hair cut looks! Maybe ill get my hair cut like that this weekend!
Populatiry hungry girl's friend: Stop being such a poop, that haircut would look horrible on you