No, this isn’t written from the child’s perspective or in child language. The sentences aren’t simple, though they’re friendly for children to read. What astonished me was how much meaning is wrapped up frequently in so few words. It is a very deft example of a writer at their utmost skill. And so rarely done so well, even in “adult” books. So yup, not simple, but incredibly packed with meaning, while still friendly for children to read.