I’ve been buying photography books for awhile now, they are interesting and (hopefully) helpful. The reasoning behind buying them varies as much as the content of the books.
There are books for all sorts of stuff: lighting the nude, shooting in crappy light, using a single flash, improving this, composing that, and all come from various types of photographers. All of which had their purposes in writing and selling books. So many approaches, philosophies on how to photograph, how does one pick their flavor, create their style, and do their thing? I don’t know, but I’m finding that learning both the philosophy behind people’s images explains some of why they shoot the way they do. Is there one right way to shoot? Nope, it’s ART, it’s personal creativity, expression, seen from their viewpoint. There may be reasons why commercial photographers shoot the way they do, the client, but they still are the eye behind the lens.
Long rambling story short, just as in life there are things we can see from images motivations, moods, and emotion; and there is a lot of things going on in the background or under the surface that we don’t know.