Were greater than Itself — though He –
Minutest of Mankind – should be —
And He — could reproduce the Sun —
At Period of Going down —
The Lingering — and the Stain — I mean —
When Orient have been outgrown —
And Occident — become Unknown —
His Name — remain —
F549 (1863) J307
This poem is fairly self explanatory and I could no better at explication than David Preest in his summery:
… Emily returns to the theme of poem 291 [F327, "How the old Mountains drip with Sunset"]. There she claimed that even the greatest artists could not properly reproduce the sunset. Here she says that if (the meaning of ‘And’ in line 4) an artist could reproduce the actual moment of sunset, his name would remain until the end of time, even if he were the ‘minutest of mankind,’ since he would be greater than nature itself.
Of course Emily herself attempted to reproduce the sunset in many poems.
But Dickinson does some nice poetic things that I think deserve appreciation. First, she varies from her more usual ballad or hymn form, adopting longer lines, using three-line stanzas, and having a (slant) rhyme scheme of AAA / BBB / BBB. The rhymes are nearly all long vowels which places a subtle emphasis on the last word of each line. There are long vowels heavily salted throughout the poem, slowing it down as if it were a long summer day or the sunset "Lingering" between the "outgrown" east of morning and the darkness in the west into which the sun sinks.
The most effective use of long vowels comes at the very end in the shortest line of the poem: "His Name – remain – ". Dickinson's use of word sounds underscores the meaning. The rhyme of "Name" with "remain" is very tight, too, with the similar-sounding "n" and "m" sounds reversed from one word to the other.
There's an assumption of artistic power throughout the poem. The artist who can reproduce a summer day is greater than a summer day. Perhaps Dickinson is winking at Shakespeare who famously began Sonnet 18 by asking, "Shall I compare thee to a summer's day?" He ends by claiming that through his poem the subject of the poem will never age or wither; consequently she is superior to the summer day.
The artist will experience similar longevity, for the name of one who captures the sunset will live on – just as Shakespeare is as immortal as his creations. The artist and their art give life to each other.
I find Dickinson's use of "Stain" to describe sunset color quite interesting. Does she mean that a true rendering would include some reverberation of, for lack of a better word, sin? "Stain" in both her her dictionary and our modern ones means "discoloration" and "taint". Or is she simply referring to the streaks and swatches of sunset color?
That line about the Occident becoming unknown is a bit mysterious. The pairing of "Unknown" with "outgrown" is lovely and perhaps it mirrors life. We outgrow our morning and noon and fade into that last "undiscovered country".