levi
Still fresh, damnit!
I've not used a Debian live image myself - what DE does it drop you into? I'd assume it'd be Gnome 3, while the Pyra will use XFCE or LXQT last time I heard - both of those DEs use the traditional desktop metaphor, using a menu as the initial graphical application launcher, while Gnome 3 uses a search box type system to launch apps for the first time. It's also a lot more heavyweight, taking CPU cycles to do pointless animations and such like, but I guess once you've launched an application in either it's pretty much equivalent.