It is silly to tell your opponents that you have a good hand when you play high-stakes poker. However, particularly good poker players say they can read other players' "tells." These are subtle and unintentional facial expressions, mannerisms, and body language that reveal what players are thinking. What would Erving Goffman call tells?

Erving Goffman develop a model called the "Dramaturgical model" which has to do with the presentation of self, meaning, how we presentate to others.

According to Goffman, we create impressions through our language and our body language. So we create impressions by our expressions.

There are two different kinds of expressions:

Expressions we give: Things we say and intentional poses and facial expressions.
Expressions we give off: Things over we have less control, it refers to the body language that "gives us away".

In the example, particularly good poker players say they can read other player tells. These are subtle and unintentional facial expressions and body language that reveal what players are thinking. Clearly, players don't do this intentionally and therefore they don't have control over these facial expressions and therefore it gives them away. Thus this is an example of "Expressions we give off"