1. Few things addle the human mind more than too much information coming through too quickly — to say nothing of contradictory information. The mind tends to shut itself off then like a circuit that locks down rather than burn out. That being so, it’s even more extraordinary to learn that “all the images” that the prophets saw “appeared to them in one fell swoop”, even the ones “that contradicted each other”, and that they were able to bear it all.
After all, wasn’t Moshe told and didn’t he envision the facts that one was “not (to) have relations with (his) brother’s wife” (Lev. 18:16), and yet wasn’t he was also told and allowed to envision that “if brothers are living together and one of them dies without a son…. Her husband’s brother shall take her and marry her” (Deut. 25:5) which seems to contradict that. And wasn’t he told and made to see at one and the same time that we’re to “remember the Sabbath day, to keep it holy” (Ex. 20:8) while also be shown that we’re to “observe the Sabbath day” (Deut. 5:12), implying two completely different notions? How could Moshe endure these inherent contradictions?
2. The answer, as Ramchal explains it, lies in the fact that “something that’s supernatural doesn’t experience the limitations of the natural world”. That’s to say that while contradictions and the like may addle the human mind, they don’t have that effect upon a mind that’s gifted with prophecy, which transcends the ways of the natural world.
Ramchal then offers the example of dreams, which evince a trace of prophecy (see Berachot 57b). After all, things we see when we dream often go against the natural course of events; all kinds of contradictory phenomena toggle back and forth across the screen of the sleeping mind then. And if that’s true (and not unexpected) in dreams, it’s all the more so true of prophetic states .
 For Kabbalistic references see R’ Friedlander’s Iyyun 61.
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.