"There's a certain Slant of light" may seem like your average Dickinsonian, lyrical poem in common measure, with alternating iambic tetrameter and iambic trimeter. But with all those dashes popping up in almost every line, it starts to sound more like a lyrical poem with staggered breathing. What do we mean by that? Well, with every dash, we find ourselves pausing for a second, almost as if the dash is a comma—even though it isn't.
And yet at the same time we sense a sort of continuance because of the dash. Take for instance lines 1-2 where we first hear about the "Slant of light" and then the speaker abruptly includes the idea of "Winter Afternoons" that's followed by a dash. At first, things sound put together and then the speaker abruptly breaks her train of thought by including only a phrase that's complemented by a dash. So essentially, Dickinson's speaker has got us all twisted up inside with this poem that sounds dissonant at times and yet simultaneously cohesive and put together. And what better way to capture that elusive "Slant of light" than with a poem that sounds just as equally mysterious and difficult to pin down?
It's also hard to pin down because the speaker tells us her poem in short lines that are often nothing more than phrases, or (in purely grammatical terms) subordinate clauses: "None may teach it—Any." Her syntax is also a bit unusual in the way the speaker tends to reverse the subject-predicate formula. For instance, in lines 7-8 the speaker tells us about the "internal difference" before indicating that it's where the "Meanings are." It's as if we get only incomplete glimpses into the essence of that light and by the time the poem is finished, it sounds as if the light is departing almost as quickly and mysteriously as it arrived.
Still, those exact rhymes that we get in each stanza ("afternoon" and "tune," "scar" and "are") help to keep the poem sounding more cohesive than dissonant. So, just as we feel as if our speaker is only giving us bits of phrases in each line like "Winter Afternoons" and "An imperial affliction," we get a neat little rhyme that serves to put the pieces back together for us. Now and then we also get a few slant rhymes like "light" and "heft" and "listens" and "Distance" that subtly keep the sound together without sounding too songlike. In a lot of ways then, the poem sounds like that mysterious slant of light.