How visible is visible followup

[ChocolateMousje]

Let me try to clarify: If the power is on, but not active (for example, a damage shield defined as a pop up weapon), should it be easily visible to casual observation to someone who doesn't know what to look for?

I don't dispute that once activated the effects are fully visible, and afterward you could pick out the source, or that it could be predefined as visible even when on but inactive (fire aura damage shield).

I just don't think that, on a first meeting, without seeing the power in use yet, characters should automatically be able to say, "Hey, force field... I'll use my NND not vs FF on someone else"

[Steve Long]

You're making a distinction between "on" and "active" that generally doesn't exist in the rules. If a power is on/has been activated -- for example, if a character is paying END to maintain it, or if a character would derive some protective benefit from it if attacked -- then it's visible, unless the rules say that it isn't, or the character has paid for Invisible Power Effects.