What does If snow be white why then her breasts are dun?

Another question is: What is Sonnet 130's purpose?

Sonnet 130, an unusual poem, turns the idea about female beauty on its heads. It offers the reader an alternative perspective of what it's like for a woman to love her, warts and all.

Another question that might be asked is, "What tone does Sonnet 130 have?" Tone conveys the mood of a poem. The tone in sonnet 130 seems mocking to me. This sonnet is interesting in that, even though it describes his lady love, the speaker seems more interested in slamming the clichéd descriptions often used to describe a relationship in poetry.

What does Sonnet 130's last two lines mean in this context?

These are two simple lines: The speaker believes that his lover is just as amazing ("rare") than any woman ("any she"), who has ever been misrepresented ("belied") through exaggerated comparisons ("false compar"). These two last lines are what the poem is all about. These lines are the punchline of the joke.

What does Sonnet 130's speaker mean when she says that she walks on the ground with her feet?

My mistress walks on the ground when she walks: This is to suggest that Shakespeare's dark lady is not a goddess. He says that she does not float in air and that her music is far more appealing than her voice.