Perspective. Haze and clarity. Both fine things. Watch as the poem embraces the antics of fog. Strong the foreground, as in, what is upon the page and background, hazy. Then a shift, perhaps wind; miraculously the background becomes clearer. Upon a poem’s second reading, what receded, doesn't.
Spice accomplishes the same with food. Chili flakes in the fish stew. Or white peppercorns. Foreground/background. Layers to taste.