exaggeration does not truly capture the beauty of the lady. Similarly, a lady's lips can never be as red as fine deep-red coral. Of course, the lady in this poem is the Dark Lady; so some of the standard or conventional similes would not apply in any case. A lady's skin is never actually as white as freshly fallen snow, but the Dark Lady's skin is the color of "dun," a very plain brown color. At this point, the reader might think that the speaker is criticizing the appearance of the Lady. Of course, this is not the case, as the rest of the poem will reveal. At the end of the quatrain Shakespeare ridicules the simile of comparing a lady's hair to fine silken strands (or "wires") of gold. Of course, the Dark Lady has black hair, so the speaker would have to then call her hair "black wires." Here the image is definitely an unattractive one. Of course, the point here is not to discredit the beauty of the lady. Instead, the point is to discredit the use of such a simile. A comparison of hair to fine golden wires is a foolish comparison, the poet seems to be saying.
In the second quatrain the speaker discredits or mocks the comparison of a lady's skin color in her cheeks to red and white roses (in lines 5-6) and the comparison of a lady's breath to the smell of a flowery or fragrant perfume (in lines 7-8). The alert reader should note the use of the word "reeks" to describe the lady's breath. The word reeks does suggest an unpleasant or even bad odor. Shakespeare is providing some naturalism here. The poet is bringing the reader down to earth -- to reality.