This is actually an issue with the PageImages extension. Presumably that needs to be updated to be aware of Wikisource covers https://en.wikisource.org/wiki/War_and_Peace_(Tolstoy)?action=info

Question. Is there ANYTHING other than convention, which indicates that something is the cover of a book ? I currently see.. a cover is defined by the community as:

• The first page transclusion on a book page,
• should be the front cover,
• which is a transcribed version of the book cover
• generally this page has a an associated image, which is the n’th page of a upload

I’m seeing several problems that have to be solved.

• page images has no concept of or way to address, a page within a multi page files right now
• covers of books are not actually images transcluded on the book pages (they are transcribed wiki pages, which might look like a cover image)
• page images of books are hard to guess (conventions fail)

There is no data that says: “book x: cover is page y of z” ? Hmm. The Index page seems to have a field for cover, but then the book page, doesn’t seem to have a back reference to the index in a reliable way ?

I think it were best if there is a hook for page images, that the Wikisource extension can hook into, to provide the image to page images extension directly, but even then it might not be simple.