A bulbous bowl on a small foot, with ridges on the side, versus a more conical bowl on a small foot, with an outward facing lip at the top. One large enough for a bowl of cereal in the morning, one small enough for a not too calorie loaded amount of desert.
One bulbous and ridged, with an outward facing foot versus a triangular bowl with a straight lip. These are about the same size and can hold a lunch size amount of rice or noodles.
A "first piece thrown" wobbly bowl, small and triangular with an uneven top, and a large bulbous, low set bowl on a thick base with ridges at the bottom. One just perfect for two scoops of ice cream and sits nicely in the hands, the other thick set enough for cereal or chips ready for dipping.