I'm fascinated by the "mirroring" aspect of the INFP as I've realized that I've been doing that all my life.
Ever since you were a baby.
Human nature, behavior, emotions, personality - it's all so incredibly complex. Anything I say here is just my opinion and subject to disagreement or correction. So much goes into our human interactions that runs deeply below our consciousness, and there's more than one kind of mirroring. Some of it can be overt, connected with social conformity, a desire to fit in, be accepted, find commonality, but I don't think that's what you're talking about in reference to yourself, so I'm going to offer a couple other ideas.
I used to think to myself that if someone does or does not like the way I'm treating them then it's (generally) a reflection of the way they're treating me or others. I've recently come upon the term "mirroring" and it's completely apt to my ways of interaction.
Looking back I've noticed that I respond differently to people here on ToL, that is, I'll respond to doser differently then A4T and again different to TH...etc. It's mirroring in action. :think:
It seems to me there's a difference between TOL (online) interaction and real-life interaction.
With regard to the way you respond to people at TOL, could it be more your adaptation of your personality to the immediate situation informed by past experience? That is, you know how it's going to go based on past interactions, so you "gear up" so to speak, to respond in kind or at their level or at their emotional place. Could that be more an experiential response than an empathic mirroring? Just a thought.
With empathic mirroring, I see it almost like a dance. A waltz, and maybe the occasional tango (if it's an emotionally-charged relationship), where you're moving in unison, sometimes leading, sometimes responding. This can be done online, but not easily.... because how can you read the nuance of facial expression or tone of voice or body language? You can't, so then you guess, you assume... and you could be totally wrong even if you're normally an intuitive person so it can be very frustrating.
But take that dance to real life, and you're reading the face, tone, hesitations, a thousand different things, no matter how fleeting - and you're anticipating and responding: following to allow them space, growth, freedom to explore an idea - or leading because you sense they're looking for guidance, reassurance, a touchstone, an anchor. You're making micro-second adjustments continuously, in real time, and your empathic mirroring is at the subconscious level, you're not aware you're doing it at the time, it's instinctive, intuitive. This can be at the romantic level, friendship level, professional, parent-child - every interpersonal interaction.
And I think you need the right personality for that dance. Some people aren't able to pick up on those nuances, they just don't have the tools in their toolbox. They're great at a lot of things, but they don't notice the little imperceptible signs that tell them they're treading on thin ice, or they don't realize that the other person is waiting for them to say something that's not getting said. However, in your real-life scenario, you're talking about mirroring another introvert. That could be a very intricate dance indeed. :chuckle: