The program playing in the background can shape a room without receiving anyone’s full attention.

Half-heard things still get in. A programme running behind conversation sets a temperature for the room: its pace, its mood, whether the voices in it are angry or gentle. Nobody is watching, so nobody notices the influence, which is precisely what makes it effective. You end up with an atmosphere you did not choose and cannot quite account for.

Try an evening where whatever is on has been picked on purpose, or where nothing is on at all. See whether the room feels different, and whether people talk more. Background is a choice too, even when it is made by leaving something running.