What is the meaning of the poem domination of black by Wallace Stevens?

Wallace Stevens chose "Domination of Black" from 1916 as his own favorite poem for the 1942 anthology America’s 93 Greatest Living Authors Present This Is My Best ... (Dial Press) with the following statement (p. 652):

The themes of life are the themes of poetry. It seems to be, so clearly, that what is the end of life for the politician or the philosopher, say, ought to be the end of life for the poet, and that his important poems ought to be the poems of the achievement of that end. But poetry is neither politics nor philosophy. Poetry is poetry, and one's objective as a poet is to achieve poetry, precisely as one's objective in music is to achieve music. There are poets who would regard that as a scandal and who would say that a poem that had no importance except its importance as poetry had no importance at all, and that a poet who had no objective except to achieve poetry was a fribble and something less than a man of reason. This lawyerly masterpiece of circular reasoning (poetry is good - unlike other areas of life - because it is good poetry), inasmuch as it means anything beyond the customary come-hither smokescreen of the artist, suggests that the worth of poetry lies in qualities beyond logical explanation, beyond formal concerns, as inaccessible to laymen as to poets themselves. "The themes of life" are the themes of poetry, but its value lies in something different that is unique to poetry. Let’s see if we can unravel this differance. Here is the poem:

At night, by the fire,

The colors of the bushes

And of the fallen leaves,

Repeating themselves,

Turned in the room,

Like the leaves themselves

Turning in the wind.

Yes: but the color of the heavy hemlocks

Came striding.

And I remembered the cry of the peacocks.

The colors of their tails

Were like the leaves themselves

Turning in the wind,

In the twilight wind.

They swept over the room,

Just as they flew from the boughs of the hemlocks

Down to the ground.

I heard them cry - - the peacocks.

Was it a cry against the twilight

Or against the leaves themselves

Turning in the wind,

Turning as the flames

Turned in the fire,

Turning as the tails of the peacocks

Turned in the loud fire,

Loud as the hemlocks

Full of the cry of the peacocks?

Or was it a cry against the hemlocks?

Out of the window,

I saw how the planets gathered

Like the leaves themselves

Turning in the wind.

I saw how the night came,

Came striding like the color of the heavy hemlocks

I felt afraid.

And I remembered the cry of the peacocks.

This poem, read aloud, is a great example of the way Stevens creates his stately yet dynamic rhythms through repetition. The same word emphasized in different ways, in different accentual structures, brings with it an eerie weight that, in this case, where multiple words are carried throughout the whole poem, unifies the whole with a stillness and grandeur. In the 190 words of the poem, the words "wind", "cry", "leaves", "hemlocks", "peacocks", "themselves" and "I" are all repeated five times, while the words "turning" (6), "turned" (3), "fire" (3), "remembered", "loud", "heavy", "tails", "room", "twilight", "striding" (2 times each) are also repeated. The phrases "like the leaves themselves" and "the cry of the peacocks" are each repeated three times (four if you count minor variations). It’s as if Stevens has invented his own style, the mournful villanelle wrought to an extreme. The repetitions encompass the elements (earth/leaves, fire, air/wind), a rare use of the first person (interesting in that context that Stevens chose this as his personal favorite), and a number of words rich in symbolic meanings, most notably the rhyming "peacocks" and "hemlocks."

Dramatically, the poem moves through an extended comparison of a flickering fireplace fire with first the autumn leaves literally reflected from the outside into the room, then to the colors of peacocks tails (and the encroaching night to the dark green of hemlock trees). Then the noise the fire makes is compared to the noises of both peacocks and hemlocks (with some questioning of who is talking and listening to whom), and finally the planets in the sky seem like the same turning of the leaves, the changing of the seasons, a holistic sense of relatedness that soon resolves both in the fireplace and outside to darkness. This encroachment of night scares the speaker, but he remembers the cry of the peacock and feels better.