I do think that the possibility to type by body language and facial expression exists.. however, so very many variables that its not good enough to rely on. I have observed 6 unique ESFJ's use the same eye contact, body language, tones, and facial expressions. Fucking uncanny. I could try to verbalize all the ques i've picked up on by type.. but I'm just not talented enough to articulate it correctly. Absolutely believe it could be done though.. with a perceptive enough observer.