so much depends
upon
Interestingly, these opening words are the poem's only moment of abstraction. In the stanzas that follow there are only concrete images. The speaker is remarking upon the importance of the wheelbarrow, emphasizing this with his use of the word "depends." It also delays the reveal of the image of the wheelbarrow itself. The speaker provides important framing before depicting the poem's central image. The phrase "so much depends" can be taken both as an invocation of the wheelbarrow's practical application as transport, and more metaphorically as invoking its central importance to the poem's other images.
glazed with rain
water
These lines follow the first direct mention of the red wheelbarrow itself. The image it creates is starkly beautiful, unadorned with comparison, personification, or emotional overtones. It simply shows the wheelbarrow covered in a light glaze of rainwater. This moment is also interesting in that it shows the wheelbarrow in stasis, as if he were painting it as a still life. This effect is doubled by the fact that rainwater creates rust, implying that this moment of aesthetic pleasure derives from a corrosive natural process. This brings out the physicality of the wheelbarrow itself.
beside the white
chickens
The chickens are an important image in that they are the first living things to appear in the poem. While the wheelbarrow remains as the central image, the images show actual activity occurring. Still, Williams constructs these lines carefully. The white chickens are not beside the wheelbarrow; the wheelbarrow is beside the white chickens. In the fragmented sentence that this poem is made out of, the wheelbarrow is still the grammatical subject.