Maybe you mean that an expert will use more specific language which in turn triggers the model to give a response that more closely matches the "expert distribution"
Anthropic published a study showing that Claude does more work for the expert user, and experts have a higher rate of "successful sessions" than novices.
That's essentially it,
It's why you should spell everything in commonwealth English to make the model think you are more intelligent ;-)
Although if models have emergent properties, it is conceivable, if unlikely, that it could have abilities that no-one knows how to ask it to do, except for perhaps in its own internal reasoning language.