A real cat is a threedimensional figure/object although a cat drawing is a twodimensional figure. The real cat has have length, width, and thickness. However, a drawing have only length and width (no thickness).
Similarly, a reflection of a threedimensional object on the water or mirror is twodimensional. For example, a reflection of a seaplane on the water is twodimensional although the plane itself is threedimensional.
