Louise Labe's Sonnet 23 is a Petrarchan, or Italian, sonnet.  A sonnet always has 14 lines, written in iambic pentameter (10 syllables per line, with alternating unaccented and accented syllables), but Petrarchan sonnets can follow different rhyme schemes. 

A Petrarchan sonnet is divided into two parts: an octave (the first 8 lines) and a sestet (the next 6 lines).  Usually, the octave follows an A-B-B-A-A-B-B-A rhyme scheme, but in the case of this poem, it is A-B-B-A-C-D-D-C.  The sestets' rhyme schemes can vary - for this poem, it's E-F-F-E-G-G.

Most Petrachan sonnets deal with unattainable, or unrequited, love.  They also often speak of the beloved (usually the woman) in exaggerated, or hyperbolic, terms.  In this sonnet, however, the woman is the speaker, and she is recalling how her lover USED TO speak of her this way.  She states:

     You used to pour out lavish praise
     For my fair face, my honey-colored hair,
     My deep, blue eyes, and for my striking flair.
     And O, my dearest one, I miss those days! (Labe 1-4)

Now, it seems, their loves has taken a turn for the worst as the result of an argument.  Still, though, in this sonnet hyperbole plays a big role: as a result of their separation, the speaker says she "thought the sun had dropped down from the sky" (Labe 8).