[These are my perceptions of the poem.]
The poem entitled "Overalls," by Robert Morgan shows the careful use of word choice, syntax and form to create a desired tone by the author.
The poem at first glance is about overalls. They are not stylish—a casual piece of clothing, they are comfortable:
...bib up to his neck holding the trousers high on his belly, with no chafing at the waist, no bulging over the belt.
While the author says that overalls make the "biggest man...look baby-like," this image is dispelled later when the man in the overalls is likened to a soldier going into battle. The author's tone (how the author feels about his subject) reflects a certain respect for this man in his "armor."
The word choice continues to be important as the author describes the details—the important functions of the smallest items on the overalls—much the way he speaks of a mere man becoming a warrior with the land:
But it’s the pockets on the chest that are most interesting, buttons and snaps like medals, badges, flaps, open with careless ease, thin sheath for the pencil, little pockets and pouches and the main zipper compartment like a wallet over the heart and the slit where the watch goes, an eye where the chain is caught.
No space is wasted; no aspect of the clothing is frivolous—the "buttons and snaps" are compared to "medals, badges," much like the decorations on the uniform an officer would wear in the military. The "sheath" for the pencil can be compared to the might of the "pen" as opposed to the "sword" (which would also be sheathed—in a scabbard); "the main zipper compartment like a wallet over the heart" holds valuable items. For the soldier, perhaps orders or a map; for the worker, pictures of family or a business letter. The watch and chain are reminders of time—what we lose constantly, that which is in short supply.
In a larger sense, the cloth used to construct the garment is compared to a map of sorts. The denim "mesas and envelopes" refer to hills or plateaus, and holes and indentations...in the earth. Morgan describes all this as:
...a many-level cloth topography.
The topography is like a surface map of the land that shows its dimensions: the peaks and lowlands, mountains and valleys.
In the last image, the overalls are a uniform. The "weapons" are "hammers and pliers," in loops like holsters (a "pocket" for a gun). The comparison continues as the "overall-garbed" man goes...
...armed and armored yet free-handed into the field another day for labor’s playful war with time.
Here, the war is not between men or countries, but between man and time, when one works hard to accomplish as much as possible in the time allotted to him—by season or throughout life.
The word choice reflects a theme of battle: man vs. time. The word order allows for smaller images to build (using "larger" images) into the larger, "overall" message—of being garbed for the "battle" at hand; details are provided in order of importance.
Lastly, consider the poem's form—in literature, form is...
...the manner or style of constructing, arranging, and coordinating the parts of a composition for a pleasing or effective result.
The different aspects of the poem, the words and their placement— mimic the "layout" of overalls—all the parts come together with exactitude; each piece contributes carefully and powerfully to the perfect final product.
Bedford Introduction to Literature (Ninth Edition)