The artist drew detailed graphite illustrations and then painted multiple acrylic paint swatches. After scanning all of the artwork she compiled the final images in Photoshop.
This is a book that can really encourage parents and children to focus on vocabulary and talk about all the different ways an animal uses its mouth. This book is useful in background knowledge because we all have a mouth, so children can understand the concept and make a connection to the text right away. You could use small mirrors so each child could look at their mouth and compare them to the animal in the book.
I see this book being a jumping off point to compare noses, eyes, ears, and anything the child wants to contrast. It is very lifelike in the artwork and that appeals to children.