I think it refers to "outside corners" or down angles... which would be for the surface bullnose, and unless they are square, you are correct there would be lefts and rights.
Ask the KD to clarify, but the bigger question is, why are you ordering the tile? Usually the installer would be responsible for the quantity, unless this is a DIY?

Bullnose with two adjacent edges bulled. Like the letter L. Corner pieces in other words.