The Art of Genes
Coen starts by introducing the idea of hidden colours - a code which determines how different parts of an organism start off the same but develop differently, for instance the different parts of a flower, or the segments of an insect. He explains how this is achieved via master proteins which can switch certain characteristics on or off. He then shows how diffusion of a chemical can lead a concentration gradient, and so a distinction between different parts of the organism. Later chapters of the book look at the place of symmetry in the development process.
The book has plenty of pictures - both diagrams of the organisms in question and works of art used to explain the artistic metaphor. This metaphor does get a bit far-fetched at times - for instance numerous artists on an expanding canvas - but I felt that it was generally a useful one, and leads well into a discussion of why development should be thought of as a creative process, rather than a predetermined path. However if you are knowledgeable in the subject then you will probably find the book rather slow going - I think it is more aimed at those looking for a gentle introduction to the role of genes in development.