It means your no fun at parties
it means she "outlines posh english people's lives". Or basically summarizes what the lives of posh english people are like, which is to say they are an obfuscation of the clarity of intelligent conversation at an unnaceptable level of incoherent and babbling self importance.
hope that helped.
Incidently I'm from Ireland and when I meet someone who needlessly complicates the beauty of the english language to sound important or to curry literary favour generally i tend to place them in the over simplified yet refreshingly clear category of the c*nt.
