A good answer might be:

Sure. Look at the body of the snowman. When the polygons are filled in the shape looks like a sphere.

Complete Picture

Here is the complete picture, with polygons filled and lighting applied (and a bit of snow tossed in):

With 3D computer graphics packages (such as OpenGL), you can ask for models of spheres, cylinders, and cones and place them in your scene where you want.

QUESTION 3:

Could our virtual tourist wander into the virtual snowscape and take a different picture?