Michel Camdessus, the former managing director of the International Monetary Fund, listens during a press conference in Lyon, France. His finger over his mouth is an example of a specific Emblem. Of course, we all recognized this as children - "Be Quiet!", "Shsssss!", "Don't Speak!". But another critical detail here is that the finger doing the "Shssssing" is his middle finger (his index finger is supporting his chin) - thus Mr. Camdessus is displaying a second, particularly caustic, emblem.
An emblem is a very specific signal that has a precise meaning and is ubiquitously understood within a culture or geographic area. When done in overtly, in the conventional position, everyone recognizes it. But in the everyday, it is often subtle and camouflaged - and it "slips out" subconsciously (Ekman). So while we all know when a teacher is attempting to quiet and unruly classroom, or one driver "flips off" another for cutting in front of them - when these emblems get packaged up and delivered by our subconsciousness in a subtly different position - they can slip by us and are more difficult to see.
While there are several other signs of critical evaluation seen in this photo, there is no doubt that Mr. Camdessus doesn't like what he's hearing - moreover, he doesn't like the speaker at all. If you see this while you're negotiating a contract, you're in for a steep uphill climb. If you see this during a discussion with your boss - polish you resume' ASAP!