This screenshot was done a very long time ago. This indicator most likely no longer work under Debian. You may try to backport it from Ubuntu, but I have no idea whether it will work the way you want it to.
I also switched to Xfce 4.8, cause despite of my tries to get used to GNOME 3 it's not for me. I use Arch and after boot it uses just 90 MB from 2 GB RAM. simply amazing, cause I do not have plain and minimal Xfce desktop, but the full desktop with LibreOffice, Skype, Firefox 4, Opera, GNOME network manager, GTK3 support and all the other goodies.