In terms of the text, I would describe this more as a reference book for people with particular interest in the periodical and the artists involved -- it has appendices and details and biographical research, which are clear but not presented with an eye toward interest for the casual reader.
A guided string of artworks made by many, if not all of the Secessionists. I'm a SLUT for a good preface and even more for detailed biographies. This one book is my whole life. This is a very personal review if you cannot tell.
Let me explain more, I could spend my entire life looking through this book and through every piece of artwork mentioned, every person who inspired the very group of people who inspired me so greatly. I am obviously biased since I'm a Ver Sacrum enthusiast. Giving this book the highest rating I can which is for me to write an obnoxious amount about nothing. But it seems fit since this book is filled with essentially that. It's beautiful and silent at times but incredibly emotional if you have the patience.
It starts as a research, you need to either already come equip with all the art knowledge or need a phone to really see the the preface and after you've gotten all the references and inspirations and generally connected things it becomes a place to absorb, I feel no shame in filling in the sides of the pages with my feelings evoked by the artworks. The biographies are sometimes on the shorter side and you can find yourself lost in the art before realizing you accidentally flipped past the biography, and at that point I would have already convinced myself to buy a whole new book on that artist.