Wendell, I have to call shenanigans on installing Gnome Shell Extensions. I installed the latest version of Debian with Gnome 3.4.2.
I've followed every suggestion I can find on the internet and can't get the Gnome Shell Extensions (https://extensions.gnome.org) to work as you described in your Linux video.
The slider on the https://extensions.gnome.org page never appears and as far as I can determine, all the plug-ins for Iceweasel are install as well as necessary packages.
So before you go spouting how much Linux sucks because you cannot install fucking extensions to GNOME (yes, I'm being hostile) Did you check the GNOME Shell Integration plugin? You did say "all the plug-ins", but that's the specific one you need. it might not have been included to IceWeasel and other Firefox-forks
Is the extension page loading in Firefox? It should. Also when you first go there firefox will ask you to allow or deny the extensions. Choose allow and remember.
Holy shit dude. You are using Gnome 3.4? Dude, we are on 3.16. Most plugins WONT work with something that old! Plus, you have to enable them in the browser when the popup offers. Kinda like when it asks about java or flash.