Placing an object such as a bag, cup or phone between oneself and another person.
Feeling uneasy a person draws a coffee cup in front of the chest and holds it there. The object becomes a small shield, placed between the self and a conversation that feels exposing.
A barrier can signal a wish for protection or distance from the person opposite. Watch whether the object is drawn in as a topic turns tense, since the timing reveals the purpose.
Objects are often placed for convenience, so look for whether the barrier appears under stress. A bag set on a lap may be there for want of anywhere else to put it.