An article of interest, called The Agony & the Ecstasy of Taking Author Photographs:
The Agony and the Ecstasy of Taking Author Photos
I'm not sure that I look like my books, but one author who certainly does is 42 year-old Benjamin Myers. He's an enthusiastic self-promoter of his grim novels, happy to pose in rugged landscapes looking hirsute and manly! As further proof of his butch, take-no-prisoners approach to writing he founded a literary collective called The Brutalists.
I reckon that the marketing of books is more about the image of the author, rather than their age.
Ah yes, his 'The Gallows Pole'. Brutalist is the word all right. I know his neck of the woods. Stark, spare, atmospheric as hell...good, great.......and also Yuk. I sympathised with the plight of the people in the valley, weavers of worsted for uniforms, laid off work after the end of the 7 year war with France. But whilst with them on their issue, and though the writing was immensely vigorous and powerful, there was not one relatable character to root for...unless it was the customs man, whom the forgers murdered.