That suggests that the writer views God as an artist who belongs to a different dimension from our world. The metaphor also implies that God is in some sense personal. Another metaphor that connects with that in Christian Theism is of humans in the image of God. That opens up all sorts of creative visions of what we are made for in our relationship to God and to one another. It should be obvious that such metaphors can never give us the logical clarity of a mathematical system, or even Einstein's metaphors for his model of relativity.
Metaphors can also be strangely paradoxical.
Beauty is skin deep, beauty is a matter of character, and beauty is in the eyes of the beholder, can all be equally true if we understand what is being said. It could merely be a choice not to use the word God. In the same way one could conceive of someone who refused to use the word beauty or love or justice. But a militant atheist is usually someone who wants to deny the existence of God. An agnostic tries to claim he does not know whether or not God exists.