In fact, the contrast.
Here, in pictures for exemple, the dark and the light.
Those are pictures taken Thursday, inside the Royal Festival Hall.
The same place, different rendering.
Different mood results.
Does it not?
The same is true with a story or a "joke".
Also it can be also the looking up, vertical then down and the difference the surprise.
Surprise can produce laughter. The unexpected. The suddenly revealed.
I learned yesterday, from Logan Murray, there is a "comedian answer" to all. A different one then usual. Another point of view. Revealing often what is under.
The best, but more often the worst that could happen.