This book is full of fun questions for little children to answer. From "Who's wearing blue socks?" to "Who's closing one eye?", there are two questions on every double-page spread which encourage children to engage with the charming illustrations and talk about what they see. Children will find being able to answer all the gentle questions satisfying. Rhyming text adds to the charm. At the end of the book, the question in the title is finally answered, for a pleasing conclusion.