This poem sounds like someone coming out of a deep meditation and giving us a very vague yet thought-driven poem to chew on for a while. The heavy use of repetition gives the poem a rhythmic feel, but the repetition echoes as a sort of flashing light to identify what preoccupies the speaker.
This poem is so short, it's almost like a poem tweet. And not only that, the speaker repeats himself throughout the poem, which means it could be even shorter if he wanted it to be. This creates a sense of unity in the poem, but also an obsessive quality in the speaker. Just like a mirror reflects an image, the speaker is constantly moving back and forth between feeling present and absent.
Here are the words and phrases that repeat:
Just like our speaker is going back and forth, the sound of the poem moves back and forth with repetition. Check out these lines: "Wherever I am / I am what is missing" (6-7). The "I am" is split between lines but it repeats. It's like a mirror reflection, but it's also movement. The phrase moves from the end of a line to the beginning of a line.
It's like this guy can't make up his mind, and it's that repetitive loop that the poem is trying to capture. If you take a look at the list of words that repeat, you can see what the speaker's obsession is: the field (place), and his constant need to move and keep things whole. So, a lot of this poem sounds the same when you read it aloud, but that sonic echo of repeated words mimics the speaker's dilemma in the poem.
Our speaker uses bare-bones phrases in simple, accessible language. He isn't concerned with a lot of flowery descriptions about nature or sensory detail about standing in a crowded subway (we're looking at you, Pound). All our speaker gives us is, "[i]n a field." His concern is with simplicity and clarity.
In fact, the simpler the speaker sounds, the more complex his idea seems to get, as he packs a ton of meaning into teeny, tiny lines. The doubling of words and breaking up of the lines makes him sound meditative and deliberate, almost like an ancient meditative mantra or something. What can we say? Still waters run deep.
Finally, the straightforward tone of this poem might also be a bit of a paradox. In a way, the line, "I am the absence" is a type of paradox, because the speaker has to be present to tell us he's "the absence."
But our speaker is so monotonous that his ideas about not existing become disturbing. What sounds calm on the surface embodies a frantic anxiety about being "absence." In fact, our speaker is so bothered by the feeling that he disrupts wholeness, and his whole poem becomes about why he keeps moving to avoid permanently being absence. So, the sonic quality of the poem, in a seemingly paradoxical nature, captures anxiety and fear in a very calm, deliberate voice.