FYI, a PR has already been submitted to change this report to include all images. It is pending review/approval/merge.
If you are comfortable in editing python files, the change is to the file in the addons sub-folder : DetAncestorReport-images/detdescendantreporti.py
OLD:
self.bibli = Bibliography(Bibliography.MODE_DATE|Bibliography.MODE_PAGE)
NEW:
self.bibli = Bibliography(Bibliography.MODE_ALL)