A scenester is someone who consciously tries to fit into a cultural scene based around a genre of music, art, film or other media. A scenester will adopt the fashion and habits of people in the scene (such as the comic book scene or the emo music scene) in an attempt to claim oneself as part of it.
The word scenester is used both as self-identification and as a derogatory statement. Someone may say, "I'm a scenester" or shorten it to "I'm scene" when identifying oneself. When used as an insult, it is usually in a snobby way suggesting, "You're a just scenester, but I'm the real thing."
The difference between a scenester and a person who is simply IN a culture is originality and sincerity. For example, a scenester in the emo music scene might think, "People who listen to emo music have shaggy black hair; therefore I should dye my hair and make it shaggy to prove that I listen to emo music." In reality, a hairstyle has nothing to do with a person's taste in music.
When people identify themselves as scenesters, they are stating their pride for fitting in with a group. Most scenesters find it comforting when they meet someone with the same image because they can assume that person also has the same interests. Most people feel a sense of belonging and security by joining a scene--because sometimes you don't know who you really are until you see it!
Some people are frustrated by scenesters and see them as trendy wannabes. Some scenesters will follow a scene that already exists without contributing to it like the musicians and artists who originally made up the scene.
Scenesters also bring underground scenes into the mainstream, which then "packages" the scene and turns it into a trend.
A good example is the punk music scene of the 1980s. Originally, punks wore ripped clothing held together by safety pins because they were against the capitalist system and therefore would not spend money on new clothes. Now, however, clothing can be bought pre-ripped and pinned as a fashion statement having nothing to do with political beliefs.
The band "Catch 22" has a song called "Day in Day Out" that expresses frustration with music scenes: "I don't need a music scene/ to tell me who I am..."