As a first impression you might misinterpret it as a book with some entertaining problems for dan players. However, once you know that the author is a professor at the Myongji University and studies Baduk and cognitive science, you will have the right clue how to learn from the diagrams. (Each example has some introductory text, which I cannot read.) The examples and their commentary diagrams are about perception, i.e. about questioning your own psychology during reading move-sequences, setting goals for reading, and using environments of reading analysis. A "solution" is shown only to be followed by a better one that also considers deeper tactical reading, more unexpected tactical moves, stronger resistance by the opponent, stronger answers to a stronger resistance by the opponent, environments also considering neighbouring groups, larger sets of possible goals, and environments considering even the whole board with its side-effects for apparently local problem solving. Often you are surprised how and in which respect your perception has been restricted. The book widens your eyes. It is worth reading for dan players, however, due to its method of teaching you should not expect too much from it.