make-theme-imagescript, that downloads an icon them package, grabs relevant, user-specifiable, icons, and arrange them in a neat montage. The images displayed are the results of running
~ make-theme-image gnome-icon-theme moblin-icon-theme
-woption. The following command should provide you with a decent overview of the icon themes present in Debian:
apt search -- -icon-theme | grep / | cut -d/ -f1 | xargs make-theme-image
I hope you find it useful ! In any case, it's on github, so feel free to patch and share.