I think I do have an internal dialogue running throughout my day, from the moment I wake until I fall asleep.
It's not a linear or logical dialogue that comes up with a solution to a problem I might have, and you might call my dialogues meaningless, but I would still describe them as dialogues because they often consist of a curious thought or question and an emotional response to those thoughts/questions. When I'm alone I actually talk many of my thoughts out loud. I find it oddly soothing.
In the example you asked us to consider:I expect the thoughts of an INFJ will be very similar to any other type to be honest. I will be curious to know more about them. If I find them attractive (more intellectually than physically), I will be friendly to maintain their interest but also a little reserved because I will want to be sure they are actually single, if they are serious, what kind of relationship this kind of person would have, and whether it is the kind I would want. If they are overly flirtatious and charming, I might be inclined to think that they are into casual relationships which would be off putting for me, because I am only interested in serious relationships. I would be more intersted in their thoughts about things other than me, so whether we shared similar values and ideals, and had similar feelings about them, rather than that they thought I was beautiful and whatever else. Whilst I wouldn't ask direct questions, like if they were single, away from the person I might try to work out the answers to my questions and find out as much about them as possible without the person knowing. I will also imagine different scenarios with the person, imagine interactions, and situations and how that person would respond to those situations. I will basically be running my vibes through imaginary tests, and seeing what the conclusion of my intuition is about that person. Weird, I know. I'm not saying this is a good thing. Of course, the more opportunities I have to actually interact with the person in real life, the better, as then my imagination won't get carried away on false premises.For dating reasons, I wonder what range of things an INFJ woman might think about when she senses that a guy may be giving her vibes.
Not sure if this was what you were asking.