I’ve been asked a writer question: Is it true that in fiction it’s essential to show something instead of just telling the reader what they need to know?
The answer is: it depends —
I started my writing career writing short stories. In short fiction, you pretty much must tell because showing would take too long. The trick, of course, is to tell in such as way as to not take the reader out of the story. It’s a technique that can be learned.
In novels, however, the opposite is true. You normally show because you are allowed a whole lot of words in which to get your story across. Even short novels are thousands of words longer than the longest short story.
Novellas — those stories that I think of as ‘half novels’ — in length are between short stories and novels and so the answer for novellas can be either showing or telling, depending on what information you want to impart, how important that information is, and how interesting it would be if you show instead of telling. Lots of leeway in novellas.
So, again, it depends on what you are writing.