hey remember the Ability Radar? dont know if anyone dissected it or a reveal was done, so a guess: the exclamation point corresponds to cognitohazardous effects, whereas the lightbulb is to equipment and infrastructure on the scene of the event (or "the theoretical extent of the power's application in respect to user's imagination" ?)
(Meri's referring to this thing)
There's a bunch of things going on here, I think, because the Radar is like, an in-universe rating given by an organisation that is dedicated to giving quick and snappy descriptions to people in, basically, fireteams who are trying to deal with/capture/subdue superhumans. It means a lot of it is subjective, especially [!].
What I will say with regards to your question is that [!] tends to be very high for cognitohazards. But for some of these, it's entirely possible to be marked 'too high' in [!], and [!] is far more subjective than any of the others (lightbulb is probably the second most-subjective).