No person has ever seen God directly, not in the true sense of "seeing" (John ch1 v18)
In fact it is impossible for a man to see God and live (Exodus ch33 v20).
These two verses confirm what reason suggests; viz. that it would be impossible for our minds (in our present condition, anyway) to take in the sight of the "fullness" of God. It would be like trying to pour a gallon into a pint pot.
Therefore a man can see at most a "form" of God; something which conveys the sense of being in the presence of God, but not a true sighting of the real thing. The most that Moses is promised in Exodus ch33 is the "back" of God, not his face (v23).
My usual way of putting it is that what men see is an image which accommodates itself to their understanding. That would explain why the image has a slightly different appearance each time. That will have been what the elders of Israel saw in Exodus ch24 v10, what Isaiah saw in Isaiah ch6, what Ezekiel saw in Ezekiel ch1, what John saw in Revelation ch4.