When it comes to ice, size does matter, not to mention shape, density and clarity. … But large cubes or spheres of ice will melt more slowly, bringing your drink closer to the temperature of the ice without over-diluting it.

Why are ice cubes that shape?

Its unique shape allows for excellent displacement and allows liquid to flow over it more easily, so there’s no messy splashing and less waste.

Why is smaller ice better?

Smaller ice fills more of the cup space by fitting together more tightly than large cubes do. So if the restaurant uses smaller ice cubes they in effect give you less soda. The drink usually comes out of the machine cold anyway, so the ice is for keeping it cold not making it cold.