In the three-dimensional and ever-fast, ever-moving visual landscape of the 21st century, books fight for a chance to be seen and picked up. Working as a journalist and stylist at British magazine i-D in London in the 1990s, I learned quickly that Terry Jones, our editor-in-chief and founder, didn’t really care what I wrote as long as the pictures were up to scratch. I don’t agree with what he said about the words—I care a lot about words—but he did have a point. Nobody was going to look at my writing unless the pictures were pretty. This sentiment was echoed by my editor at HarperCollins when I wrote my book, Legendary Authors and the Clothes They Wore.

To be fair, a book about the intersection of authors and fashion certainly invites great pictures, and I worked for almost a year putting files of images together to illustrate my theory: that the originality and distinctive creativity of many writers’ clothing style is fascinating and resonates today when the fashion industry looks to original characters for inspiration. I can’t say that all books would benefit from pictures, but a book’s cover is the first engagement many have with the author, and what’s on that cover is crucial. It needs to communicate what’s inside. As in fashion, a cover reflects something of the author, even if it’s only what he or she has given the green light to.

I was incredibly lucky when it came to the cover of Legendary Authors. When I sent in my initial proposal and rather audaciously suggested that an image of Joan Didion by Julian Wasser would be an ideal cover, my editor at Harper Design, Elizabeth Sullivan, immediately agreed. As this was the first book that I had written and put together completely alone, I had very little understanding of the picture research journey; it turned out to be a bumpy and rough ride.

The first thing I had to do was get hold of my perfect cover image, and since Didion’s office is constantly badgered by inquiries from all sorts of people for all sorts of things, my inquiry was most definitely at the back of the queue.

So I approached Wasser, the photographer who had taken the picture I wanted. He told me in no uncertain terms that he preferred to deal with an art director. Of course he did: Wasser is an internationally famous photographer who has taken images that have shaped eras. His graphic eye for composition is unparalleled. He shoots surfers, hippies, musicians, protesters, and artists alike, framing them exactly the way he has framed celebrities such as Jack Nicholson, Anjelica Houston, and Elton John—with a sharp and thoughtful eye. Not for nothing has Didion said that “anybody who had their picture taken by Julian felt blessed.”

Wasser described Didion to me as “low-key and very approachable.” He captured her charm with a series of images, one of which I used for my cover, of her smoking, standing in flip-flops by her Corvette Stingray in 1968. It was his idea to photograph her by the car: an exciting, make-a-statement car that juxtaposed cleverly with Didion’s understated style.

Wasser didn’t tell her what to wear, though. One fashion editor remarked to me after my book was published that she adored the dress Didion has on in the shot; another couldn’t fathom its appeal, saying it was scruffy.

I know exactly what I think: the dress works not because of the dress but because of the way Didion inhabits it in her own, uncomplicatedly stylish way. She looks effortlessly attractive, and the outfit is better because it’s unexpectedly worn with flip-flops. These clothes wouldn’t look the same on anyone else.

That’s the point of my book, and that’s why I am still amazed and thrilled that Wasser’s picture of Didion is my cover. It communicates what I tried to articulate about great authors and clothes: it’s not what you wear, but the way that you wear it that counts, and character is key to success, in pictures and words and fashion.

Terry Newman is the author of Legendary Authors and the Clothes they Wore (Harper Design, out now). She lectures at University for the Creative Arts in the U.K. and lives in London.