We can go too far with showing not telling. This is the poem I was originally going to recite at the Get Writing Conference last Saturday:
Mary had a little lamb.
She also had a duck.
She put them on the mantlepiece
To see if they'd...fall off.
It's just not as funny. Yet we're still relying on the audience identifying and then supplying the missing word, exactly as in yesterday's poem. I think it's not as funny for two reasons: the missing word is generally considered ruder and cruder, and the substitution weakens the joke.
When you're writing, you're creating a world. You want to lure the reader into your world and keep them there. They're usually keen to stay, but can be jolted out. By being crude, the reader is startled out of their comfort zone. I was interested to learn that several friends preferred my later novels because there was less 'bad language'. Now, I don't think there's much in any of my novels, but I took their comments on board. The 'bad language' had jolted them out of their comfort zones and away from my story world.
And then there's the substitution. I think this weakens the joke by pointing out that it IS a joke, a contrivance. The reader doesn't feel as clever as they did in yesterday's poem when they did the work and substituted the word. Instead, it's a trick, and they're the ones being tricked. The subtext runs: You're expecting this rude word, but - ha ha - it's something else quite innocuous.
So there has to be a balance. If we use showing not telling, but make what we're showing too obscure and difficult, it becomes too much like hard work and the reader will give up. If we mislead the reader, the reader will turn away. Sometimes telling is the right thing to do. Part of the writer's job is learning about the balance and getting it right.
When I told my partner of my poetry plans for the talk at the Get Writing Conference he said I must have balls of steel (!) to contemplate reading out such material in front of a group of strangers. Yesterday's poem got a laugh, today's wouldn't. On Saturday I got the balance of smut:crudity right. Tomorrow maybe I won't. Who knows? It's all a matter of trial and error and, balls of steel or not, isn't it fun to be playing and experimenting?