It is sumptuously illustrated with color diagrams and photographs. An author trying to explain general relativity to the public faces two problems. The first is that of concepts. The second problem is that the mathematics of general relativity is not simple. The mathematics of special relativity is simpler because its based on a geometry that is flat - not Euclidean but still flat.
Calculations are relatively straightforward.
The mathematics of curved geometry is well beyond what can be really explained in a popular text. Wheeler like many authors before and after him, must resort to analogies. He devotes a chapter to the field equations that shows the relationship between space-time and matter. Here he is less successful. Even if the reader does understand the analogy, he or she will be no closer to understanding what General Relativity is about.