Stanza 2 Summary

Get out the microscope, because we’re going through this poem line-by-line.

Audacious socks,
my feet became
two woolen
fish,

So the socks are on, and they transform the speaker's feet into fish! What?! Just wait, it will start to make sense.
The socks are first described as "audacious," or daring and bold. Bet you didn't know socks could be this exciting! This might be considered an example of personification, or giving human attributes to an inanimate object. After all, how can socks be bold?
And it's not just the socks that are coming to life here. Next comes a metaphor in which the speaker's feet are compared to "two woolen / fish" when they're in the socks. They transform, but not completely, because they are still woolen. The feet retain some of the wooliness of the socks even as they are magically turned into fish. Check out "Animal Imagery" to read more about these mysterious feet-fish (feesh?).
The poem takes us into a magical realm where beautiful socks can transform feet into fish, but it still leaves us with one foot on the ground (see what we did there?), reminding us that they're made of wool.

two long sharks
of lapis blue
shot
with a golden thread,

Just when you thought it was safe to wear your socks again… they turn into sharks!
This is an extension of the metaphor started in the previous lines, which compared the feet to fish. Sharks are even more streamlined than fish (no scales!), and these ones are "lapis blue," which is a reference to the bright blue, ultramarine-colored mineral "lapis-lazuli." (Check out the "Animal Imagery" section for more, if you are so inclined.)
Just as in the image of the "woolen fish," we can't let go completely of the sock-ness of these socks. They may be bright blue sharks, but they've got a "golden thread" shooting through them.
That thread of knitting yarn tethers the socks in reality, even as the figurative language transforms them into sharks.

two mammoth blackbirds,
two cannons,

Forget reality, these socks are transforming, like Merlin and Madame Mim in The Sword in the Stone! First they're blackbirds, then cannons.
These lines are more in a series of metaphors that started way back in lines 17-20. First they are gigantic blackbirds, which really doesn't say much for the daintiness of the speaker's feet.
(Look at the "Animal Imagery" section for more on our fine-feathered friends.)
Then they become cannons, which is a departure from the animal metaphors (fish, sharks, blackbirds) that have appeared up to this point. The sudden appearance of the cannons is an abrupt reminder of humans and war after the natural images of fish and birds.

thus honored
were
my feet
by
these
celestial
socks.

These lines slip into hyperbole, exaggerating how great these socks could possibly be. These socks are heavenly, and give honor to the speaker's feet.
But it's not just the socks that are heavenly. Check out the word "thus" in the first line. This refers to all the transformations we just went through—from fish to sharks to birds to cannons. Those magical changes are the honor the socks do to the feet. The socks make the feet into something beautiful. That's the honor.
The cannons from line 26 combine with these lines to turn the sock-wearing into a ceremony, like in a 21-gun salute. All throughout the poem, the socks and the feet have been transformed from their ordinary status and made into something special.
The poem repeatedly uses images that make the simple act of putting on socks into an almost religious ceremony. Here the use of the word "celestial," which means something like heavenly, gives the simplest object, a pair of wool socks, a mystical aspect.
Try thinking about that next time you're rolling out of bed and pulling on some tube socks for class! It might make you at least hunt for a pair that matches.

They were
so beautiful
that for the first time
my feet seemed
unacceptable to me,

All that accumulated magic that the poem has given the socks finally has its result—making the speaker's feet look ugly in comparison. (Maybe they just need a little nail polish.)
This moment is an epiphany for the speaker. It's the"first time / my feet seemed / unacceptable to me." After so much praise for the socks, which are really a pretty ordinary gift, it's jarring that the speaker wouldn't see feet as magical and mystical, too.
The point is that it's only after meditating on the beauty of the handmade socks that the speaker also thinks about feet in a different way. The whole poem forces the reader to look at ordinary objects in a different way.

two tired old
fire fighters
not worthy
of the woven
fire
of those luminous
socks.

We're still looking at those feet, and now they are compared in a metaphor to two firefighters (which is also an example of personification), and the socks are the fire.
The fact that the feet are firefighters and the "luminous / socks" are the "woven / fire" puts the feet in opposition to the socks: they are fighting them, trying to put them out.
The speaker still reminds us of the woolen nature of the socks, never letting them get so far lost in the metaphor that we forget that they are real, and what they're made of. The fire, for example, is "woven." This anchor in reality has the effect of making poetry itself a real, everyday thing—it never gets too far-gone in figurative language without coming back to the ordinary topic of socks.