I always thought her eye was part of the
reason for some of the other things she does.
Since her face is non-symmetrical, with one side visibly lower than the other, the side-ponytail, the bangs parted above the eye, the head tilt, the camera angle usually from one side, all of that kind of offsets the asymmetry of her face.
Haven't you noticed how in most photos, she's usually taken from her left side, while she tilts her head right?
The geometry of her face is just a little off, and that's part of her look. As a result, if you try to straighten it out, it doesn't look right:
If you flip her face horizontally, it
really doesn't look right.
It's amazing, really.