so much depends
a red wheel
glazed with rain
beside the white
My own take on the poem is as under:
When the poet says so much depends on a red wheelbarrow, he is speaking of a red wheel-barrow, the one he is seeing right now. Not the red wheel-barrow, in the way one makes a universal statement.
Once we have decided the context, i.e. the one the poet is referring to, the rest is merely a description of the red wheel-barrow as an object in the specific context of the poet’s seeing it.
Thus we are concerned ,basically, with the visual aspects in the poet’s perception.
The visual aspects emerge by looking on the key words: “red”, “wheel” separated from “barrow”, “glazed with rain” , “rain “separated from “water”, “beside”, “white” separated from “chickens”.
Red wheel-barrow : Red makes it prominently visible from a distance, from which the poet is presumably seeing. The red of the wheel-barrow contrasts with the white of the chickens. Wheel is separated from barrow to emphasise their independent existence from barrow. Wheel is capable of moving independently but imparts motion to the barrow. Red wheel-barrow is a static-visual image with possibility of movement., the potential to turn a static-dynamic image.
Glazed with rain: Red of the wheel-barrow sports a glaze by rain-drops, a white of glistening. “Glazed “ is from rain already happened but drops are its potential for movement. Hence rain and drops are separated.
Beside: Beside is positional with reference to the white chickens, defining the locus of the red wheel-barrow in the poet’s visual map. But “beside” has a mystical quality, with a potential for escape, for dodging . The chickens will not stay there long. How does one define the locus of the barrow ?
So much depends upon the poet’s perception, the reader’s own.