As a suggestion, dillo could helpfully have /etc/mailcap entries for
image/gif, image/png and image/jpeg since it can display those. Various
other browsers such as iceape have such entries. Perhaps something like
the debian/mime file below (to become /usr/lib/mime/packages/dillo).
Currently update-mime crunches /usr/share/applications/dillo.desktop
"MimeType" into an /etc/mailcap entry
text/xml; dillo %s; test=test -n "$DISPLAY"
Is this generic XML? Does dillo do anything with that, or does text/xml
mean xhtml? If so then an entry for that in this mime file, or if not
then maybe dillo.desktop would be reduced.