While at Old Man's Cave the Headmaster explains to Rose and Briar that "When you stand on the shore, all you see is the riverbank...but from the height of a sparrow, you can see the course of the entire river" (28). Soon enough he is revealed to be speaking more than literally when Rose finds a sparrow in one of her dreams. She intends to focus on it, so that she can learn to control her dream, but gets distracted by a small stream that she wants to admire. This stream is revealed to be the dreaming, as explained by the dragon she rescues from it: "Do you know what river this is? It is the dreaming itself!" (34)
Rose literally walks away from the sparrow who would allow her to see the entire dream, to look at just a small part of the dream.