Really not all is fine.
With libevas-loaders I see many other icons that I've not seen before.
But pavucontrol requires gnome-control-center-data package to be installed.
% grep Icon /usr/share/applications/pavucontrol.desktop
there are a lot of other icon themes that provides
multimedia-volume-control (adwaita-icon-theme for exmaple, which is
installed on my system), but I see pavucontrol icon only with
Really I'm not sure if this is an E bug.