Hoi,
I added a book that is very notable in the Netherlands to Wikidata. It has
several authors and most of them do not have Wikipedia articles. There were
no photos available either. I did ask one of the authors for pictures and
now there are four.
The point is very much that exactly in the same way as it can be done for
Wikipedia articles we can seek pictures to illuminate our work. Reasonator
does show the pictures [1] wherever these people are mentioned.
PS I am also seeking pictures of all the authors together to add to the
book itself.
Thanks,
GerardM
[1]
https://tools.wmflabs.org/reasonator/?&q=22070167