In "The Red Wheelbarrow" we see a harmonious relationship between an manmade object (reflective of the human world) and nature. The red wheelbarrow sits unused and neglected, while rain seems to wash it clean and make it look brand spanking new. Chickens hang out with the wheelbarrow and keep it company. It almost seems like this wheelbarrow is part of nature. The absence of humans in this scene makes us feel the wheelbarrow's loneliness and makes us appreciate nature for paying attention to the wheelbarrow.
The rain is positive force that washes the wheelbarrow clean, giving it new life.