what is the effect of the broken sentences with each line ending in the word we

The structure of internally rhyming couplets (technically internal rhyme because every line ends with "We") is layered over with more instances of soundwork. For example, Brooks doesn't just rhyme "late" and "straight" in the third stanza, she gives each line's respective verb a hard "k" sound which contributes to the symmetry and flow of the lines.