as for a look in the eye... this has nothing at all to do with NFs being special or anything... but there is a look that NFs have sometimes, which is like they are attentive to you in a friendly manner, but also like they're looking through you - like they're looking for more information than they're getting. i would venture to say it could be an actual NF/non-NF difference, present in specific movements of the eyes. i wouldn't be surprised to hear that Ns and Ss, and Fs and Ts, have differences in their eye movement patterns, since we tend to pay attention to different things. the "looking through" is probably an N thing and the close people-attention is probably a F thing. maybe it's just a natural reaction to realize when people are looking at and responding to the same things that we do. i also think it would seem a fair statistic that NFs in particular would pick up on an odd difference like this, not because we're better in any way than the other types, but because we're both pattern and people attuned.
Good description. I would add that this same feeling can be there also without eye contact. I don't know how to describe it, though. Maybe it's a bit like absent-mindedness without actually being absent-minded. If that makes any sense.