(n.) a bitchy girl (usually Caucasian blonde), somewhat attractive, or cakes on the makeup to make it seem as though she's attractive. Usually wearing something designer (Tory Burch, Chanel etc.) iPhone and BMW keys in hand. Shiny girls have a sense of entitlement and usually have no knowledge of the world around them including pop culture, politics, or important world problems.
The concert was fun until that shiny girl cut you off.