I did more research with notify-osd. rythmbox actually sends 2 notification requests with embedded icon data, and the second one contains the cover art. I have re-opened bug #229197 that was mentioning that issue in rhythmbox.
-- rhythmbox does not show album art in notifications https://bugs.launchpad.net/bugs/332356 You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to rhythmbox in ubuntu. -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
