I don’t think there’s a ‘rhetorical’ name for this technique. It’s effective and often creates a significant shockwave in the minds of readers and listeners.
Good example. The Enid Buzz FB page asked What’s the coolest prize you ever won?
Lots of money prizes, small vacations, side of beef, pizza for a year.
The best soft answer: A fifth of whiskey at Bingo when I was 8. I had to give it to Dad, and I just got a Coke.
The hard answer: A free trip to sunny Vietnam.
= = = = =
Here’s the opposite, from the same source. An unexpectedly good soft answer to a hard question.
What’s the best advice you ever received?
Don’t take a job east of where you live.
Requires a bit of thought…. Ah. You’ll always be driving into the sun.