This concept book was one of my daughter's favourites when she was two. The book follows the journey of a yellow box that transforms from just an unboxing experience into a helicopter then a lorry containing a horse, to the lights switching on and off from windows in a building and well many more transformations. Each box concept illustrates a set of opposites up - down, in - out, on - off, inside - outside. The best bit about the book is that the interactions invite both play and re-telling of stories about each very simple action or pair of opposites. Early on in the book, there's a series of boxes within further boxes - akin to Russian dolls with a tiny mouse hidden in the smallest box. Storytelling has expanded beyond the book's space as my daughter delights in hiding the mouse and re-discovering him having first searched under the duvet, pillows and bear. The interactions on each page invite play and because the nature of the book is more about basic pictures and movement, a two year old can tell stories in words and gestures about what will change or what has changed. The book reminds me of paper prototyping and animation basics - it's simple and engaging through being inherently interactive and not just a flat surface.