Lines 81 through 84 have a structure called chiasmus. (A famous example of chiasmus is the President Kennedy line: “Ask not what your country can do for you—ask what you can do for your country.”) The first clause goes: adverb, adjective, verb, subject, or "twice beautiful / is beauty." The second clause changes up that order: subject, adverb, adjective, or "and what is good is doubly / good." Chiasmus balances oppositions in order to create an overall sense of unity or completion. Here, Neruda uses chiasmus to create a formal symmetry in the lines that mirrors the beauty and goodness he is describing, while also marking a subtle pun: beauty and goodness are doubly appreciated when they are married with humble function, as they are in the case of the socks. But the socks are also twice as beautiful and good because there are two of them. By reversing the structure, Neruda draws attention to the figure of doubling itself, and gets us to realize the power of his pun.
The sentence ends in hyperbole: these socks are “celestial” meaning heavenly, or to continue the light metaphor established by the word “dusk,” filled with the glow of stars. In Spanish, the word translated here as "celestial” is also the name for sky-blue.
Ode to My Socks Questions and Answers
The Question and Answer section for Ode to My Socks is a great
resource to ask questions, find answers, and discuss the novel.