A question about wording of stunts

[gojj]

I feel the best way for me to ask this question is by giving an example. In Your Story there is a stunt called Make-up Artist:
Make-Up Artist: Given enough time, you can
create very convincing disguises, ones that will
hold up to deeper inspection (although not to
careful scrutiny and magic). Any attempt using
Investigation or Alertness to see through your
disguise is at an additional +2 difficulty.

Is the reason it doesn't simply say "+2 to your Disguise trapping" because magic can be used to see through the disguise without using Investigation or Alertness?

[EdgeOfDreams]

Yeah, I think it's because there are other ways someone could see through the deceit besides Investigation and Alertness.  For example, let's say you're posing as a foreign dignitary from a non-existent country. I might allow a scholarship roll for a character to know there's no such place, poking holes in your disguise.

[Veet]

Its because that trapping specifically states it only works against passive awareness, it's not good against investigation without the stunt.