In these opening lines of the poem, the relationship between the speaker and Maru Mori is laid out for the reader: they're friends, and this friendship is demonstrated with the giving of a gift of socks.
knitted with her own shepherd's hands, (4-5)
The socks, we find out here, aren't some store-bought six-pack of interchangeable white socks. They were made by hand, which implies real friendship between the gift-giver and the speaker.
thus honored were my feet by these celestial socks. (27-33)
The socks, since they signify the friendship of Maru and the speaker, honor the speaker's feet and, in an example of synecdoche, the speaker too.