I'm usually more interested in the setting or background of the author photo than in the author himself. The props can be quite interesting. The costuming, too.
I notice that photos of Dean Koontz often show him with a golden retriever, which reminds me (and probably many others) of his novel Watchers, which is my favorite of his. Another author photo memory: In one of her earlier novels, they had Olivia Goldsmith all tricked out with blond hair and a Vogue pose. In a later one, there she was, a brunette who looked like a writer not a model wannabe. I much preferred the later photo.
It seems a tradition to tart up romance writers or try to make them look like old money. Thriller writers are often equipped with dark glasses and tough-guy outfits. There's the famous pic of Tolkien, every bit the Oxford don out in the quad with his pipe. Susanna Clarke's pic in Jonathan Strange was so glammed-out, I didn't recognize her on the cover of Locus, looking so...ordinary! Someone once said that SF writers have the eyes of children, with Ray Bradbury the exemplar of the phenomenon.
Interesting topic. I'll have to go back and check out some photos on favorite books.
I've never considered the author photo in purchasing a book. I do have a preference for photos on the back flap rather than on the back cover, which is where there should be either a good summary, cool blurbs, or more art.
