He demands to know how his cruel beloved can deny his love when he constantly sides with her against himself. He forgets his own identity, treats her enemies as friends, and fawns on anyone who earns her frown. Even a glare from her makes him immediately punish himself with sorrow. He respects nothing in himself that would refuse to serve her; all his best qualities are busy worshipping her flaws, commanded by her eyes. The logic is twisted: love has become a total erasure of self, a form of self-attack. The mood is one of desperate, suffocating adoration—painful to witness.
Then the closing couplet delivers a sudden insight: she loves those who can see, and he, being blind, will never be that. There’s bitter acceptance here, but also a stubborn devotion that doesn’t let go even when he knows the truth.