What I interpret from the last sentence is, "if you judge a thing's value by yourself it is Fi, if you judge a thing's value by what other people's value judgements are then it is Fe."
If that's the case, I disagree. "Value" or "what something is worth" isn't objective, can't be objective. "Value" doesn't exist in objective reality. If you look at what people generally value and come to a conclusion, you are not making an Fe judgement, it is Fi again. Only this time you are recognizing Fi in other people or groups of people and it is of course born from an intuition if you're looking at it from a broad perspective.
Your question already contains the one word answer. "Imagining", thus Ne or Ni. Acting based on someone else's emotion can be all four judgement functions. If I'm trying to influence someone to whatever end I desire, I can judge it from an Fe perspective and act in accordance to that for example. If I'm trying to compare said emotion to my own impersonal understanding of emotions, it can be Ti. There can be countless examples for countless situations and it all depends on the strengths of functions in question.
