According to the description in the book "Friends with Thorns", the top of the book is a bird's nest.

Friends with Thorns is a book published by Beijing Education Publishing House on April, 2065438 1, by Zong Jiehua. The Four Seasons of Childhood series contains excellent prose works by Zong Jiehua, a children's literature writer. Guided by the writer's childhood rural life experience, it brings readers to know the countryside, get close to rural life, get to know wonderful "friends" in the fields, feel the lovely kindness of rural children and the simple friendship between children, discover the real fun in life and appreciate the gifts and benefits of nature. Call on us to protect nature and care for our animal friends. These words depict a vivid and beautiful picture, which opens a simple and beautiful window for readers to get a glimpse of the touching place of rural life in the book.