How does E. B. White use imagery in Letters of E. B. White?

Imagery:

"The Blue Grass is hard to describe. The region must be very like parts of England. There are rolling downs where sheep, duroc pigs and horses and cows graze. The grass is a luxurious blueish-green, and the heavy oaks and beeches give the landscape a park-like effect. At first we couldn't figure out what made the region so different from anything we had ever seen, and finally we realized that it was because of the complete absence of weeds, underbrush and indiscriminate foliage. It is as if there were a great gardener stalking through with a magic trowel, pruning and hoeing," (Chapter 2, p. 41).

"There is a magic to this state of Montana. Of course we have not yet come to the mountains nor to the 'scenery.' But there is someting about Montana ranch country so wildly enchanting as to be almost fearsome. Stand on the plains in the valley of the Yellowstone; watch great herds advancing grimly, like the ranks of an army, into the sun. The leaves of the aspens quiver down by the banks of the Yellowstone. And you don't know anything of what they whisper," (Chapter 2, p. 50).