Answer:
This is an example of territorial marker, more specifically a central marker.
Explanation:
By definition, nonverbal is the communication that takes place without depending on words, written or spoken. It may happen through gestures, body language, looks, attitudes etc.
In the situation we are analyzing here, Kristen is using a nonverbal clue. Without saying a word to anybody, she is communicating that a certain seat is taken by her, and that she intends to return to it. That is an example of a territorial marker, more specifically a central marker. A central marker is an item that is placed in a territory to reserve it for a specific person.
