It is about Rav Hutner and others who straddled the world of Slabodka and Berlin university.
(Actually that is inaccurate. Rav Hutner is the only one on the cover who learned in Slabodka and according to Berlin University records he was never a student there but you get the picture)
People pay a lot of money for such books because it is very validating for them to read that Gedolim from the Yeshiva World went to Berlin University along with allegations that they didn’t necessarily agree with all of the Yeshiva World Haskafa.