If this checkbox is marked, then an image of the distribution of brightness from the emission model of Mars will be displayed on the results page. If not marked, then no such image will be displayed. An example is shown below, for a viewing geometry of:
       Sub-Earth Latitude = -19.6
       Sub-Earth Longitude = 200.5
       North Pole PA = 344.0
       L_s = 238.8
where you can see some variation across the disk (not only limb-darkening), and the effect of the south polar seasonal ice cap (the dark spot on the bottom left).