Comment by BUZZY_BEE on Ennead - Chapter 32

@BUZZY_BEE The mirror is making him give into his inner desires. Horus has a part of him that wants Seth carnally, but he supresses it because he knows it's wrong. The mirror amplifies that feeling and throws away all his sense and reasoning, all the control he has. Horus is not a bad guy, actually. All humans have those thoughts, but we know it's wrong and so they'd never act on it. It's just that the mirror is making him completely encompassed by this thought and emotion, so his mind is gone right now.