These are lips that have had lip gloss added to them to make them more shiny. Recently glossy lips have been very popular for women and especially for teen girls to increase their sex appeal. Super glossy lips make a woman look as if she has been giving fellatio all day, which is a bad look for a young girl IMHO.
This trend in glossy lips in teens is a part of the Teen Lust Industrial Complex, most noticeably seen in teen pop sensations Britney Spears and Christina Aguilera. Shows like Dawson's Creek where the slutiest character Jen, played by Michelle Williams, has such glossy lips that they look power buffed.