Here’s what would happen to an individual who’d fall into a prophetic trance. He’d suddenly find himself to be in a dreamlike state while not necessarily asleep (since one could experience a prophetic trance while awake). Perhaps the closest experience we have to it is the quiescent, semi-somnambulant state we ourselves drift off into right before actually falling asleep or coming awake, when we know who we are but aren’t quite prepared to do anything about it.
The experience might be very short-lived or it might last a while, but the prophet would always be unconscious for the duration, since one couldn’t be communicated with on a prophetic level while in a conscious state.
Once he’d be in that state he’d begin to sense something appearing before his eyes, but indirectly so. Things would appear to be filtered through a series of subtle or more blunt skeins of vapor, and the prophet would have the sense that he was looking through smudged lenses.
That’s to say that he’d indeed be “seeing” something and would be aware of everything it was doing, but he wouldn’t be able to quite catch the thing’s outlines or many of its finer details.
Hence, prophets (other than Moses, as we’ll see) could never quite clearly make out G-d’s Glory outright because of all the “signal interference” as we’d put it. But that’s what they’d be seeing, in its various manifestations. Throughout it all and despite the impediments the prophet would still and all be very aware of what he was seeing and confident in the veracity of his experience.
It’s just that some prophets would be able to see more, and more clearly than others. Since the lenses varied with each one. Despite his level of prophecy, though, every true prophet was able to catch sight of the essence of what he was seeing and would know for certain that he was being communicated with by G-d Almighty.
The prophet would indeed understand that his perceptions were being affected by the number and depth of the lenses accompanying them, but he’d also be aware of the makeup of each lens and why it had to be there.
Another element entered into the picture as well. For not only was what he saw affected by the lenses, the images were also expressed metaphorically and where thus open to interpretation, much like dreams are (after all, as we said, a prophet was often communicated with in dreams).