When shown, you can right-click on them to get information about them. This is especially useful with the Moon, which has thousands of named craters. In the case of Mars, you can select among three bitmaps.
Few objects have three bitmaps.
If your viewing location is not on the earth, you can look back at the earth and see it with any of three different bitmaps. Both options are considerably faster than the bitmapped options. Using the slider bars, you can modify the brightness and contrast used for the planet bitmap. You can set the size, position, and tilt of the rectangle. This may be used to show the area covered by a camera or CCD image.