Anthy's point of view.
After Anthy Stabbed Utena, she couldn't and didn't look at her.
She knew what she would see. Betrayal, horror, pain, shock, Anthy knew Utena would see through what she had to say,
and knew Utena would see she had been to weak to refuse to do this.
Utena would see she had failed. Utena would see that Anthy was just a miserable weak girl, and worst of all,
Anthy would see Utena begin to fade.. That strong, vibrant, vivacious, invincible girl, just...fall.....fade...and Anthy would rather have fallen with her.
So she wouldn't look.