how does shakespeare describe his mistress in sonnet 130?

Shakespeare makes no attempt at deification of the dark lady; in fact he shuns it outright, as we see in lines 11-12: "I grant I never saw a goddess go; / My mistress, when she walks, treads on the ground." Here the poet explicitly states that his mistress is not a goddess.

She is also not as beautiful as things found in nature, another typical source of inspiration for the average sonneteer: "My mistress' eyes are nothing like the sun; / Coral is far more red than her lips' red." Yet the narrator loves her nonetheless, and in the closing couplet says that in fact she is just as extraordinary ("rare") as any woman described with such exaggerated or false comparisons. It is indeed this blunt but charming sincerity that has made sonnet 130 one of the most famous in the sequence.