Fuji implemented what it calls Digital Split Image manual focus in some previous models. It uses the on-sensor phase detect system to kinda-sorta simulate a rangefinder patch. Basically you have a rectangle in the center of the frame, displayed in monochrome, with four rows. The rows are offset when slightly out of focus, and bringing them into focus lines them up. It's not the quite the same as a rangefinder double image, but it's not too far off.
The X100T added that focus aid (and a magnified view with peaking as well, if you prefer that aid) to the optical finder. You get the standard optical view, plus an EVF feed in the corner that shows a magnified view of the frame—by default the center, but you can move that point around. A half-press of the shutter switches it to a view of the entire frame so you can confirm that you've got the shot just right, all the time you get the optical view, with some room around the framelines to see outside the frame.
Pretty neat. I had a very brief hands on, hope I explained it well enough—I was on the phone with my Fuji rep when the press release came through trying to wrap my head around it. Having the camera in your hand to try it out really solidifies how it works.
