In another life, an instructor gave my graphic design class the following assignment: design the cover of Time magazine with yourself as the person of the year. One student merged a childhood photo with a photo of a flower for an Alice in Wonderland effect--a tiny little girl sitting beneath a giant flower. It was a cute and memorable trick with scale.
Scale is as important to successful writing as it is to visual art. In a story or article, however, "scale" morphs into something more like "emphasis." A lot depends on what you intend.
If you write with too much emphasis on one thing, you may wind up with a rant--a mutant child, or a Georgia O'Keefe flower. Of course, that may be what you intend. If you give every part of an article or story the same level of emphasis, you could wind up with (at least) two different effects: 1) a minimalist composition--child and flower, lost and unrelated, in an expanse of space, or 2) a cacophony--the equivalent of a verbal Jackson Pollock. Again, one of these may be just what you intend.
My point is this. Train your awareness of the various design elements (scale, rhythm, balance, composition, color, etc.), how they translate from one genre to another, and what effects you can achieve through intentional use.