this may seem somewhat crazy but i have this idea that you can get a vague idea of a feeler's primary or secondary functional attitude based on the way they smile and their eyes while smiling.
it may be just me but i've noticed for a bit now that extraverted feelers' smile seems, i don't want to say forced but definitely more formal than a introverted feeler's smile. as if, the Fi person's smile is more playful or casual. with the eyes too i've noticed a trend where when a Fe person smiles their eyes kinda stay wide or go wider and when a Fi person smiles they more often do the opposite and i guess "smile with their eyes."
maybe this only applies when taking pictures or in a work setting as opposed to when hanging out with friends or w/e but yeah. i figure it's something worth running by you guys to see just how crazy i am :p
i'm bringing this up btw because i met what i *think* was an enfj the other day and i decided to revisit the topic and possibly get some feedback.
just to be clear i love both ways of smiling. there's no right or wrong way to do it... the only wrong thing to do you could say would be to not smile when the situation warrents it or if thats just how you feel.
one thing in particular i like about Fe primary or secondary people is that i don't have to always reflect their smile back at them for them to keep it up. it's like once they know i like them that assumption is more or less set in stone so i can be my usual self, which is to say not bursting with emotional energy but rather giving my subtle hints of affection, and that doesn't affect their energy towards me to the same degree as a Fi primary or secondary person.
example would be the other day i was buying some new shirts (amazing for me) and the girl at the cash register came at me with a nice smile and some enthusiasm (esfp i would guess) and i just kind of ignored it since i wasn't in the best frame of mind at the time. after that while ringing me up she went totally cold and i felt like a big asshole for not returning the smile and ruining this little encounter. anyways, this edit has gone on long enough to i'll just finish it here.