And maybe this is bullshit.
Maybe she's really a mirror, reflecting back what you are. Like a planet orbiting a sun, that becomes upset when her sun doesn't shine like it should. Of course, if you aren't that strong, then what's reflected isn't that strong. Plus there's nothing to say that the mirror doesn't have a few flaws as well.
A mirror needs light to bring it to life. This could explain the female truism of "just be yourself" - so that she can reflect that, instead of some weak image that isn't the inner you. This could also explain the popularity of the song "Bring Me To Life" by Evanescence. Inner experience, inner demand, of the female begging the male to make something of her in his reflected greatness.
It also sheds light on why women follow the herd, fads, fashion, etc. All manifestations of trying to reflect some form of identity that they don't really have. It possibly explains feminism: envy of what men have, just by being men, and attempting to take on that identity. An attempted definition of themselves because there is no other definition available.
No mirror-woman would be truly comfortable with reflecting the weak, needy men of these days. She wants a strong light to bask in and reflect. Thus she chooses the strong light of the asshole and jerk: it's better than the other options available.
So if women are mirrors, that makes men the biggest narcissists of all. We bathe in our own reflected light.