Although it covers a plethora of topics, what really binds it together is the idea of 'strange loops,' and how loops are existent in most everything, how they signal information, how they come in various steps, etc, etc, etc.. I'm sure the author would disagree with that summary actually, but it's the best I can do.
In finance for example, it's prompted me to more actively search for loops in any given analysis, and sometimes at a much more macro level. In politics, I've ended up thinking a lot more deeply about some loops of how civilizations progress and ideologies change.
To summarize: The book does a fantastic job at showing you how all of these loops are present throughout computer science, physics, chemistry, music, art, and practically everything imaginable. Once you realize the existence of these loops that you were previously oblivious to, you start to search for them more actively. You should definitely check it out if this sounds interesting!