From the first time I heard this song, I figured it was something about a model with a drug addiction, which is certainly a real-life issue--and in the bigger picture, a commentary on the whole glamour scene.
To me, Miranda represents women victimized on several levels: the abuse (emotional and/or physical) of a father, the pressure to live up to idealized images, the perpetuated fraud that the world of glamour is actually glamorous and, ultimately, Miranda's plunge into drugs to escape all of it.
Then again, maybe I'm giving this song way too much credit. Mabye it IS just another slam at Ms. Heche . . .