In the release notes is mentioned that the gthumb image viewer package has
been added to the distro, however it is not installed by default and is not
present among the list of packages which can be selected during the
installation (or launching redhat-config-packages).
Maybe it should substitute GQview which is another gtk image viewer but still
based on gtk-1.2.
It is installed by default in our current trees if you perform a gnome-desktop
install. I'm closing this as rawhide since it's working for us internally.