* lisp/image-dired.el (image-dired-thumb-update-marks): New function that makes the marks visible in the thumbnail buffer (bug#49988). (image-dired-thumb-margin, image-dired-thumb-mark-color): New user options.
* lisp/image-dired.el (image-dired-thumb-update-marks): New function that makes the marks visible in the thumbnail buffer (bug#49988). (image-dired-thumb-margin, image-dired-thumb-mark-color): New user options.