Sociologist Randall Collins uses microsociology and the concept of microexpressions to examine the Mona Lisa:

The purpose of micro-sociology is not to be an art critic. I only make the venture because so many popular interpretations of the Mona Lisa blunder into social psychology.  But reading the expressions on photos is good training for other pursuits. Paul Ekman holds that knowledge of the facial and bodily expressions of emotions is a practical skill in everyday life, giving some applications in his book Telling Lies. And it is not just a matter of looking for deceptions. We would be better at dealing with other people if we paid more attention to reading their emotional expressions—not to call them on it, but so that we can see better what they are feeling. Persons in abusive relationships—especially the abuser—could use training in recognizing how their own emotional expressions are affecting their victims; and greater such sensitivity could head off violent escalations.

Facial expressions, like all emotions, are not just individual psychology but micro-sociology, because these are signs people send to each other. The age we live in, when images from real-life situations are readily available in photos and videos, has opened a new research tool. I have used it (in Violence: A Micro-sociological Theory) to show that at the moment of face-to-face violence, expressions of anger on the part of the attacker turn into tension and fear; and this discovery leads to a new theory of what makes violence happen, or not.  On the positive side, micro-interactions that build mutual attunement among persons’ emotions are the key to group solidarity, and their lack is what produces indifference or antipathy. And we can read the emotions—a lot more plainly than the smile on Mona Lisa’s face.

Watching for microexpressions definitely makes social interaction more interesting. Ekman’s work suggests telltale signs on people’s faces reveal their true underlying emotions and also people tend to have very quick initial expressions before they put on their face or mask of what they are trying to express. Goffman’s ideas about impression management still apply, we generally are trying to save face and maintain our social status, but it is harder than simply saying the right things or acting in the right way as our facial expressions can still give us away.