The illustrations in the book (made by Tony Ross) are very funny but also very useful as they help us for example to outline easily granny's profile. In the first chapter there is an illustration with granny in which we can see, among other things: what she is wearing (the floral print dress and the mauve cardigan), where she keeps her packet of Murray Mints or (and that's the funny part) we can see from where does the smell of cabbage come.
Another funny illustration can be found in chapter four. Here, the author intervenes in the story by giving the readers a tip on "brushing the teeth" (better said - avoiding to brush teeth) in six easy steps.