You recognize the character immediately as being right off the Characters list. He hasn't said anything yet, but you know him because he is an example of typecasting. There are a host of ways to be typecast. Whereas stage actors are shuffled around quite a bit, allowing them to play all sorts of roles, it's a different story with movies and television.
This is not entirely the fault of casting directors. When Ed O'Neill left Married... with Children to spread his wings as a dramatic actor, audiences laughed the instant he appeared onscreen in The Spanish Prisoner. An extreme example of this is I Am Not Spock (and also I Am Not Leonard Nimoy).
Meta Casting is playing off this Typecasting to push it into another realm of familiarity.
Tropes Are Tools. There are some actors whose typical role has become known so well that as soon as you see them in a movie, whatever it is, you know it's going to be awesome/hilarious/full of asskicking/etc. (CinemaSins, for example, lampshades this with the comment whenever he appears in a movie in a normal presence, "Liam Neeson is not killing anyone in this scene.") In the world of fan theories, this practice also has a tendency to make fans believe that those characters played by a typecast actor are secretly one and the same.
When lampshaded in the work itself, this becomes Adam Westing. The opposite is, naturally enough, Playing Against Type.