First, consider the whole poem. It reminds me a little of the Shakespearean sonnets which contain quatrains and a couplet. Wordsworth's sestets (lines of 6) are made up of a quatrain followed by a couplet. Each line in the poem also has 8 stressed and unstressed syllables very similar to the rhythmic device of iambic pentameter which was also employed in Shakespeare's sonnets. These 8 counts of syllables per line also remind me of how dancer's learn choreography-- in eight-counts. This is profound since in the second stanza the daffodils appear to dance as well.
Also, looking at symbolism in the second stanza helps to analyze its meaning. Wordsworth compares the many daffodils outlining "the margin of a bay" with the stars. It seems as if Wordsworth employs a hyperbole (or exaggeration) to dramatize his excitement for the vision of the daffodils as well as to emphasize the surprising number of them that he sees. The other comparison he made was with that of the milky way, which in a way could look like a margin of a bay, too, as far as shape is concerned. He shows great visual images here because many, if not everyone, know(s) what the milky way is and can relate to his comparison.
In sum, Wordsworth uses rhythm, imagery and hyperbole in the second stanza, along with the use of a specific rhyme scheme (abab cc) not unlike that used in Shakespeare's sonnets.