If you scroll down you see:
"I’m a Cybercorps student, meaning I’m on a scholarship that obligates me to work for the goverment in security for at least 3 years after I finish school."
Firefox has had those kind of profiles for a long time, they just aren't the most accessible thing in the world.
But yeah, you can access them from about:profiles or also via the command-line with "firefox -P". If you want to use it more extensively, there's also extensions available for easy switching, like for example Profilist. https://addons.mozilla.org/en-US/firefox/addon/profilist/
Very nice, I played a bit around with it but there is 1 thing that bothers me. The sliders all start at the left but the value it represents isn't at the left. Some sliders should start in the middle to be right.