The mountain icon is the 'landscape mode' which you use when shooting things in the distance or outdoors. The instruction booklet says that at this setting, the camera will focus from 2.5 meters to infinity.
Landscape mode...as oppose to portrait mode (if off) I guess. This camera doesn't have an true explanation of what this does much like all the cameras we had back in the 80's and 90's.
If this works like what a more advanced camera does, landscape mode would just be a smaller aperture (larger f-stop) which will make everything in the picture in focus. Portrait mode would be (in layman terms) the center subject in focus and the rest is blurred (bokeh, google it you'll know what I mean). this allows the one thing in focus to stand out.