1. “The prophets saw various grades of light … ascending or descending,” Ramchal continues, “moving along or standing still,” and the like, much as we’d see physical phenomena moving about in our realm. But it must be understood that theirs was a supernatural rather than an ordinary vision. And the overarching point is that they were able to “discern and conceive of G-d’s provisions for and management of” the universe based on the makeup of those visions.
“So, for example,” Ramchal went on to illustrate, when the prophets saw “a circular, encompassing image — one without (discernible) left or right sides, or top and bottom”, that represented the way G-d interacts with the world in general and in broad terms. But when they saw “a linear image” with various dimensions and subdivisions, unlike the more amorphous image above, that represented G-d’s specific interactions with the world based on a person or nation’s spiritual standing, place and time, etc. But let’s explain.
2. G-d has two different ways of interacting with the universe: either in broad terms or in quite specific and tailored-to terms. That’s to say that He oversees and interacts with creation in total in general, and lays out broad rules, over-all goals with general expectations and universal concerns. In those instances G-d sees to it that the universe as a whole moves along like a mighty ocean, with all the order, roar, and rush inherent to it and with a rhythm of its own, but with no specific concern for details.
In other instances He concerns Himself with each and every detail as if dipping a finger in a small bowl of soup and accounting for the way each ingredient moves the other and is itself moved, changed, and reconstituted in the process. This latter style depicts the way G-d interacts with humankind most especially, when He takes our moral or immoral interactions with each other into account with a keen and discerning eye for details.
3. That principle explains a lot. So for example when G-d wanted to illustrate to His prophets His great capacity to affect “and interact with all of creation in an all-encompassing manner — in a way that affects everyone and everything equally, and with no one overlooked or unaccounted for,” Ramchal explains, “He has it appear as if a light from His Being surrounds all of creation much the way the sky over-covers everything”, alluded to by the statement that “spread out above the heads of the Chayot angels was what looked like an expanse, sparkling like ice, and awesome” (Ezekiel 1:22).
When He wanted to illustrate His function as a judge, “He had Himself appear as a king sitting in judgment upon a throne, with charity on His right side and judgment on His left”. When He wanted to illustrate to His prophets “the variety of His capacity to contend with the world, layer upon layer,” that was illustrated by the Talmudic dictum “What does the earth stand upon? Upon the foundations. And what do the foundations stand upon? Upon the waters…. And all of them stand upon G-d’s arms (i.e., shoulders)” (Chagiga 12b), as if G-d stood at the core of it all, bearing it all.
When He wants to illustrate how everything unfolds in an orderly and planned manner, step by step, “He has a ladder appear with rungs leading down to the world”. When He wants to illustrate how certain individuals “are closer to Him while others are more distant from Him” in relative order, He’d produce the image of “levels lying within other levels, like inner or outer chambers, or like one piece of clothing covering another”, and the like. All of this was to allow His prophets and their listeners to understand G-d’s ways in the world .
 For Kabbalistic references see R’ Friedlander’s notes 511 and 513; R’ Shriki’s notes 184; and R’ Goldblatt’s note 7.
Rabbi Yaakov Feldman has translated and commented upon “The Gates of Repentance”, “The Path of the Just”, and “The Duties of the Heart” (Jason Aronson Publishers). His works are available in bookstores and in various locations on the Web.