files/gobby.desktop-r1 has an icon entry for 'gobby.png'. No such icon is actually put into /usr/share/pixmaps and so gobby has a blank menu entry in kde/gnome/etc. The following is an icon taken out of the gobby tarball and a patch against the existing ebuild so that it uses the icon.
Created attachment 86456 [details] Gobby Icon
Created attachment 86457 [details, diff] ebuild patch
Upstream fixed that and there's definetely an icon in the latest version...