So its really all under the radar and you’d have to read between the lines. SFs will generally do certain actions to be polite, to fit the image of what society terms a “nice” person. An NF is personable and treat you as individuals. NFs are much more genuinely interested in you rather than trying to fit a warm image, if that makes any sense. NFs are more naturally nice whereas for SFs its more out of what it means to be nice. But its still very vague because sfs and nfs have different feeling functions as well, but that’s kind of the general gist from what I’ve gathered!