I see where you're coming from (though I also have to agree with the others that don't consider I am... to be a rock album, but that's beside the point), and I've noticed this, too. A lot of her rock-feeling songs that nearly all people would agree as being rock (Talkin' 2 Myself, Decision, (don't) leave me alone, About You, ect.) have her in short hair. A lot don't, however. It may be, though, that she sees this as a more rock-esk look. Rock is rebellious in some degree, and many rocker chicks have short hair, because it's not so girly. That may be where she's coming from.
