A brilliant book. It manages to explain a very complicated process of develpment of the embroy by focusing on the fundamental mechanisms. In particular it makes clear the fact that all forces working during development are in a certain sense local, that is, there is no overarching direction or plan. Every cell is doing what is natural for it at that specific place given its internal and external context.
A most important point that the book brings across is that the phrase "gene X is responsible for feature Y" is extremely misleading. It is a short-hand for the scientific statement that when one alters gene X, for example makes it non-functional, then feature Y of the embryo or the mature organism is in some way changed or dysfunctional. This does not mean that gene X contains all information required to produce Y. The genomes is not a blueprint of the organism, it is more like a recipe for how to produce the organism given a suitable environment, a recipe where many genes are involved in creating each feature of the organism.