The concrete image

The concrete image seems to be the thing: with that, the poem is likely to have something. Without it, it swims upstream to be heard (mixing my metaphors). But the image always says something about the person who's observed it: who noticed it, and why? Is the image self-consciously poetic ("gossamer wings") with the intention of making the observer seem like sensitive soul? Clever wordsmith? What then? Even humility is a pose.