I created some e-books in epub (using Python) with a cover page and cover image.
The e-books work fine, except for one thing: the cover image does not show in the file icon/tile on my MacBook and Kindle.
Using Calibre, I can mark the image I use for the cover as cover image. Then the cover shows on my MacBook as well as on my Kindle.
Is there a way to set this property manually in the epub?
In Python, I created all the chapter files and other required files, zipped the folder and changed the .zip extension to .epub. After setting the cover image in Calibre, it is no longer possible to unzip the .epub to see what has changed.
Any suggestions on how to solve this?
https://www.w3.org/TR/epub-33/#sec-cover-image