Something I rant on about sometimes is the idea that the "single iconic image" is effectively, largely, mostly-but-not-entirely (my position varies a little), dead as a form. That is a discussion for a different post.
As a book guy, though, I'm going to take a few lines to rationalize books as the Proper Format for photos, to see how that flies.
As I mentioned in an earlier post, video isn't a good home for still photos. By controlling the pacing, video/movie takes away from the viewer the ability to contemplate, or skim, pictures as they come. You're stuck with whatever the director thinks is the right thing. If the director wants to give you any real time to look at a picture, he or she is sure to Kens Burns the thing to death because it's motion right? Gotta have stuff moving around, or the primates will wander off!
I've argued that still photographs work better in sequences and collections. Each photo is essentially an instant, pulled out of the time stream and presented to us. It's hard to make a complete statement with that, and even if you do the viewer cannot help but wonder if it's an accident. This is different from a painting, in which (usually) it's all deliberate, and furthermore it's possible to construct the thing with whatever elements are necessary to make a complete statement.
Photographs also do extraordinarily well with accompanying information, such as captions, supporting text, that sort of thing. There may be other artifacts.
Enter the book, loosely considered (include pamphlets, magazines, flyers, a handful of prints stapled or bolted together, and so on). It retains the viewer-controlled pacing, permitting the contemplation and skimming so integral to our understanding of photographs. It permits, indeed it encourages, sequences of pictures. It allows supporting text in whatever shape and quantity you like.
I am abruptly convinced that the "single iconic image" is a stale holdover from the days of painting. This was explicit in the early days with the Pictorialists consciously copying the tropes of Victorian painting (allegorical pictures with tons of composited elements literally telling a story, hand-working, impressionistic camera usage, etc and so on). It was carried onwards to the present day under the banner of the Fine Print. The Ultimate Goal is a single large image which you hang on the wall like a painting; the single image that is self-contained.
This is absurdly limiting, at best, and I think one can argue (and I intend to!) that it's a poor fit to the medium.
Books are, in fact, the right end result for photographs.