Given the current interest in different psychological and personality types, that kind of carefully-managed public persona feels quite "one size fits all".
It may be as you say. I have not seen the pictures and I know nothing about the writer in question, so I have no way of knowing whether you are wrong or not. What I am saying, though, is that we shouldn't be too swift to condemn as false and "carefully-managed" what may, in fact, be personal and heartfelt. The woman in the photos may be acting out one of her own private fantasies. Does that relate to her writing? Well, it might. It might tell us something about the kind of book she writes. Those pictures might be saying to readers on behalf of the author, "If you are like me, the kind of girl who dreams of running through a night forest in a long white gown, you might like my books." She might even—who knows?—be enacting a scene from one of her own books.
What I am trying to say is that people who are successful at that sort of thing may be able to put the most
interesting parts of their
authentic selves into pictures and images, and so attract readers who mark the writer down as a kindred spirit, the kind of person who will be able to deliver the kind of story that appeals to them. Someone who shares their dreams and inmost fantasies, but unlike them is able to translate those into words and put them on the page.
For some of us, exposing ourselves in such a personal way may be a horrifying thought. Many writers are intensely private people. And some are so accustomed to being misunderstood and labeled as weird by others, the image they try to present to the world (when they are willing to present an image of themselves to the world at all) may be one of studied conventionality. "Look," any picture of themselves they deign to share may be saying, "I am an ordinary person, perfectly normal. See me in my t-shirt and jeans, just like any other regular guy (or gal)."
Being shy myself, I understand that sometimes people need their armor, they need their protective coloration. But what I ask now is, "Does that
sell books?" Would it not be better to present another side, equally genuine, of themselves? (And if it would be better, is it even possible to steel ourselves to do so?)
Take someone like me. Back when my first books were being published (and supposing that the internet was even invented, if social media was even a concept in those bygone days, along with all its new opportunities for self-promotion) would "ordinary suburban housewife raising four children, who also writes books" be the right image to promote, or would it be something that proclaimed what is
equally true, "I may live an ordinary sort of life most of the time, but I have
Imagination, dammit."
Or take your own books, Toby. I have seen author photos of you dating from the time when you were producing all those
Space Captain Smith books. You look quite jolly. You are laughing right into the camera. It's a great image for the man who writes humorous books. (Utterly impossible for some of us to copy, since we are too stiff and self-conscious to laugh, or even smile, or even smirk, when a camera points our way. But on you it looks good, it looks natural.) But the guy who is writing the
Dark Renaissance books? Maybe you need some pictures portraying that side of your personality.
Or not. I am simply letting my vaunted imagination ramble where it will, making guesses and suppositions as it goes. I really don't know much about self-promotion.