IMO, it is other way round - the other person will judge your aikido by how you react to his/her grab or attack.
Both are true. The person grabbing will judge nage by their response to the grab. That was the OP's point.
My point is that the person being grabbed will also judge uke by the nature of their grab. Often people who feel the need to "test" someone in this way don't realize how much they are revealing about themselves.