Maybe they're using an accelerometer to detect the angle (and possibly even distance from the user, if they can, like if you turn the camera on close to you then move it away) to crop into a sensor that's otherwise exactly like a point and shoot. The image in the site appears to show a transparent classic reflective LCD panel as the viewfinder (like the type you'd see in a basic calculator, without the reflective background), and the camera is ever so slightly above the panel. The math probably isn't that hard for someone trained in how all this works.