You are always trying to understand it in context, even if, as far as you are concerned, at that point in time, it has not necessarily anything to do with you, you still want to know why those people are laughing.
Man sollte Lachen immer im Kontext verstehen, auch wenn man selbst zu dem Zeitpunkt gar nichts damit zu tun hat. Man möchte trotzdem wissen,  warum gelacht wird.