Can't you sleep little bear?

In every spread of this book, except one, there is a picture of the big bear with the little bear. On that particular spread, the illustration was drawn through the perspective of the big bear.

The Boy, "Mummy, where is the big bear?" The Mummy stops reading, looks at the picture. How to explain perpectives? Says, "The big bear is behind you." The Boy looks sideways at The Mummy. The Boys eyes starts widening and slowly, very slowly, turns his head to look behind him. The Mummy realises what she has said. Literally. The Mummy wants to laugh but decides not to. The Boy is looking behind him now, "WHERE?". The Mummy quickly turns the page and says "Here. Look. The big bear is here!"