Yeah, what is being asked is a little confusing to me. I can easily verbalize my feeling when with close friends and family. However, I've been re evaluating my ne/fi ni/fe.. I feel like I may have been mistyping OR my fi has recently adopted what would look like alot of Fe "values". The catch is that it is a recent (last year or so) thing.. because in my teens and most my twenties I believe I was fi as hell. Pure positive emotions are difficult for me to express, like when I've fallen in love it has not been easy for me to just say it, and even once its been said and returned I can't say it all the time. As soon as something seems expected or status-quo it becomes a danger, inauthentic.. and I will refuse to allow what is so meaningful in myself to become tainted by external factors.
Observing any kind of injustice or abuse to other people and animals is almost unbearable at times. I empathize so much that even very silly things others won't think twice about can have a massive impact. However, I don't cry easily of often and I prefer to be alone when this happens, as I am extremely uncomfortable and vulnerable. It is much easier for me to communicate (via voice and facial expressions ) positive emotions, but even then I don't like to take it too far and become too gooey in front of others, I am emotionally naked when I do it, I have to know you well. It's like saying to a stranger "come into my humble sanctuary, take off your jacket and poke around at all that I hold dearest."
I just don't know how to describe this any better, honestly. I think what your asking is backwards. Fi and Fe could potentially express the same thing.. with fi being a little more reserved because of that emotional nakedness factor. The real issue is where is it born from.. how does the emotion originate? Internally or externally. I may even be confused on this and maybe someone else can help me out.. because my feelings are born from within my own internal model, which is why It doesn't matter if the majority says this is right or wrong, or this is acceptable or unaccepable.. fi users wont give a rats ass about that. You'll often hear them say "I don't care what others would do, say, feel because I inherently know this to be true" (or right or whatever).
I admit I am still confused on the actual process of fe and fi though.. because it is absolutely impossible for me to understand external origination. When I adopt values that appear fe-ish.. it is not so much on a gut-emotional level. The initial emotion is sourced internally, it is pure and raw but then undergoes a testing against external models. I suspect that fi combined with ne and te can actually appear Fe-ish at times..and know that other fi users have commented on this as well. I can sit with my own self and feelings for some time rather comfortably, but eventually I will seek to connect and express the sentiments to others. To do this I seem to heavily rely on Ne and Te. Fi on its own is a very beautiful but lonely place.