A teenyscene is like a teenybopper. Whereas teenyboppers are generally 9-10 year old girls obsessed with such acts such as Eminem etc, teenyscene, or a tennyscener generally is any girl within the ages of 12 - 16 that is obsessed with such 'Britpop II' acts such as Arctic Monkeys, Milburn, and The Kooks. It is most probable that these teenysceners have a MySpace account that has most of the new bands featured in the NME magazine's 'Radar' (new music) section in their MySpace profile 'Music' section.
Under the surface, these teenysceners were probably 10-12 years olds that were obsessed with princesses, Smash Hits and the like, until they discovered that liking them would not get them very far, so did everything else and liked everything else that they thought was 'cool'.
Not to be trusted/liked/talked to.
Teenyscener 1: Have you heard of this new band called Arctic Monkeys? They're well buff.
Normal Person: ...