What does it mean to say "the creator thinks about the world"?
As limited human beings, it makes sense to say that our thoughts about something are less than the thing itself - the map is not the territory. I may have a design model of an electronic system, with apparently detailed descriptions of what materials are where, and how the signals evolve, and how the physical device slowly changes or degrades over time. But no matter how good my model is, it is not the physical thing, and the physical thing will always differ from my model if I look closely enough.
Further, it is characteristic of human minds to be inconsistent about thought, in time and space. Wishful and dishonest thinking, incoherence, contradiction, inconstancy, distraction, neglect, and many other defects of thought are a constant part of how we think. We are suspicious (correctly so) of errors of thought; thought can be good, but it is never perfect, in our experience. But what would an infinite, omnipotent being think like? A being that can keep track of every particle and field in spacetime? Our human limitations would not apply.
For God to know things about the physical universe, without error, God's model of the physical universe must be perfect. Since the physical universe contains many dynamically divergent processes, it is impossible to perfectly and meaningfully know the universe at one time only. If God thinks perfectly, and not just schematically or abstractly, about the universe, this implies that God's mental model is as detailed and accurate as the physical universe itself. God's mind may indeed contain an infinitude of other thoughts besides those about the universe, but the thoughts about the universe must match or exceed the universe itself in complexity and detail.
So if these thoughts are at least as detailed as the universe, as big as the universe, and non-divergent with the universe, then there is an exact simulation of the universe in God's mind.
Does it make sense, then, to talk about two universes, a thought universe in God's mind and a "physical not-God" universe, that God controls and maintains in exact lock step with the thought universe? That is possible, but pointless. There is no point to having the non-mind copy; it does not accomplish anything, beyond acting as a conceptual crutch for the anti-panentheists.
This does not mean God is contingent on the universe, or that we can learn all about God from the universe itself. Our knowledge will always be limited by the ways we perceive, and the thoughts our minds are able to store. It merely means that God's thought is sufficient for existence, and that creation may be no more than a rigorous and honest thought.
MORE DRIVEL, to be organized later:
It is true that all that we can learn about God is in this universe for at least a short time before we become conscious of it; all our perceptions and thoughts are instantiated in physical matter, and the immediate precursors of those perceptions and thoughts are instantiated as well. The precursors may have precursors extending throughout spacetime, or they may have antecedents miraculously inserted just before we perceive them. But all we can know of God manifests in the physical world. There almost certainly is otherness that we cannot perceive, and there may be perceptions available to some people and not to others, but God is not limited to the sum of our perceptions. His presentation to us is bound to the world, but He is not.