Message? Quite a mixed bag really. I've recently changed my approach with mix CDs after realising that you can't go shoving your opinions down everyone's throat and have them like it ;)
Basically I now always limit my mixes to 12 songs at most and less than an hour so as not to bore (challenge?) people. For this mix I wanted to put one of my own songs on, then realised how vain that is, and then let that guide the mix! The songs are therefore all loosely related to vanity, either in the song, or in their choosing. Does that make any sense at all?