Provides a handle: (i) for Photo Mugs grasping, and (ii) provides a snappy breadth of the mug that is insulated from the hot fluent by distance.
The mug stores some heat from the beverage, and so prevents it from cooling too quickly. The chart of a mug helps insulation: (i) thick walls asunder the beverage from the cool external air, and (ii) an indented base separates the beverage from the surface upon which the mug is set. The shape of the immoral forms the characteristic O-shaped stain, so often seen upon desks and documents.