I can explain this one! When the knob only has one set of hi/lo, it controls the burner's heat as you'd expect, and it all works in the same direction. Those with multiple hi/lo sets control the heat and the size of the burner, since there are 2 (and on one, maybe 3?) concentric heating elements available for that knob.

I've had something similar for years, and have never had an issue. I'm even less likely to accidentally choose the wrong knob since the single-size one tends to have a looser feel to it.