The LCD monitor is larger than that of the S9600, 2.5 inches diagonally with 230,000 dots. Like the previous model it is articulated, capable of tilting 45 degrees down or 90 degrees up. As monitor screens go it's pretty nice, with good contrast, a fast refresh rate and bright enough for daylight use in most situations. It is also slightly recessed, which helps to avoid scratches and finger marks.
The electronic viewfinder is a bit of an oddity. It has a resolution of 200,000 dots, but it is of an unusual type, called a "field sequential drive" display, whereby each dot displays red, green and blue colours channels in a rapid cycle, in theory producing a much sharper image. It works very well, producing an exceptionally sharp display as long as the camera is perfectly still, but if you move the camera at all it produces psychedelic multi-coloured after-images which are a bit disconcerting, especially on panning action shots.
The FS in the S100FS's name stands for Film Simulation, which is one of the camera's new features. This mode is at the top of the menu, and provides a selection of four pre-sets that are supposed to simulate the appearance of specific types of film, including Fuji Provia general-purpose filme (the default setting), the high-saturation Fuji Velvia favoured by landscape photographers, as well as portrait and soft settings. In practice this mode is a bit of a gimmick, since even at its highest setting the S100FS can't match the dynamic range or colour depth of actual film, especially Fuji Velvia. That's not to say that the film modes are useless; they do produce noticeable and useful effects, but if you want to use film you shouldn't have bought a digital camera.
Another new feature which is rather more useful is the enhanced dynamic range mode, which boosts shadow and highlight detail, traditionally weak points for digital sensors. Fuji's HR sensor already has very good dynamic range characteristics, so this mode should give it a big advantage. In practice the effect is actually fairly subtle, but it does work and produces good results in high-contrast situations.
It's also worth mentioning the pop-up flash, which is on an exceptionally long armature, lifting it well above the lens to reduce the effects of red-eye. It is also exceptionally powerful for such a small unit, with a range of 7.2m. The S100FS also has a hot shoe for connecting an external flash, and even an X-sync socket for connection to a studio flash system.