Well, they've definitely been created by a neural network.
My belief is that it's the animal that underpins the conscious mind. The same animal we start out as at birth, but grow beyond (some more than others). Dreams are it's way of interpreting the sea of sensory input we absorb, but being an animal - a ball of instinct wrapped around a pattern matching algorithm - it can't read, or count, it doesn't really understand any of it at all, it just recognises how things are usually related (not entirely unlike the AI image generators) on an instinctual level. Occasionally, on waking, the conscious mind will catch a glimpse of what's happening and try to contextualise it, applying more complex, learned thought processes to fill in the blanks and explain the nonsense, but dreams rarely make sense in their raw form.