In Shakespeare's Sonnet 130, the speaker compares his love to various other images of beauty and shows how she falls short in many ways. Her beauty cannot hold up to the magnificent colors, sounds, and smells of the world; yet, despite this, he loves her still and believes his love can withstand any limitations she possesses.
First, the speaker compares some of his love's facial and bodily features to other everyday objects, including the sun, coral, wires, and snow:
My mistress' eyes are nothing like the sun;
Coral is far more red than her lips' red;
If snow be white, why then her breasts are dun;
If hairs be wires, black wires grow on her head (1-4).
All of these common objects, he states, surpass his love's features in their own ways. Her eyes are not as bright, her lips not as red, her skin not as white, her hair not as golden. Additionally, he talks about her deficiences:
I have seen roses damask'd, red and white,
But no such roses see I in her cheeks;
And in some perfumes is there more delight
Than in the breath that from my mistress reeks (5-8).
Saying she has pale skin and bad breath only serves to draw attention to her negative features, which would seem to imply that the speaker is not truly happy with his love. The speaker tries to be more positive in the next line, saying that he "love(s) to hear her speak," but he seems to ruin this sentiment with his next words:
... yet well I know
That music hath a far more pleasing sound (9-10).
He additionally points out that she seems to lack poise and gracefulness in her movements, for, while a goddess moves seamlessly, "(his) mistress, when she walks, treads on the ground" (11-12).
After such a long list of colorful, image-filled complaints, one would think the author would end on a negative note, but instead, he culminates his comparisons with a positive assertion:
And yet, by heaven, I think my love as rare
As any she belied with false compare (13-14).
He believes his love is "rare" - that she is special, unique, and worthy of praise - and he recognizes that his love goes deeper than her appearance. While in this particular sonnet, the reader doesn't get a full picture of what it is the speaker so loves or admires about his beloved, other Shakespeare's sonnets present a fuller picture of his thoughts and sentiments on this subject. This sonnet, however, uses powerful contrasts and imagery to reveal the depths of his love.
The sonnet is Shakespeare Shakespeare showing his superiority over fellow sonneteers. He is attacking their use of cliched metaphor and simile.