"Show, don't tell."
How many times have you heard this advice? A lot, I suspect, because it's good advice. In fact, I've given it countless times to students and writers over three decades.
But is it the right strategy for every writing situation? (Hint: no.) Remember that in all kinds of writing, what appears in the finished work must serve the reader. If your reader needs quick, simple, unemotional information, telling is actually the correct move.
In an executive summary, the EVP doesn't need 20 pages of explanation on the lead up to the committee meeting tasked with the project completion.
In a novel, the reader doesn't need a blow-by-blow of the long commute to the office (unless that particular commute is an inciting incident for thematic reasons).
In a memoir about saving elephants in Thailand, the reader isn't going to care about your spelling bee win in sixth grade, no matter how spectacularly you triumphed.
On the other hand, when you need to provide emotional depth or convey something more artfully that flat statements can evoke, that's when you want to show. Showing puts the reader in the scene through sensory details, so they can "experience" the events for themselves as they read.
So what does "show, don't tell" really mean in practice?
"Georgia hated mornings. She poured herself a cup of coffee, glanced at the clock and realized she was already ten minutes late leaving for work again."
"Georgia shuffled into the kitchen, rubbing the sleep from her eyes. The coffee pot gurgled as it brewed, filling the air with the sharp scent of dark roast. She grabbed a chipped blue mug from the counter and poured herself a cup. Blowing away the steam, she spotted the clock's numerals glowing over the oven: 7:40. Her stomach twisted. She gulped, wincing as the coffee burned her tongue. 'Not again. Not today.'"
Notice in the second example ("show") that showing does not mean overloading the reader with detail for the sake of detail. Just a few well-chosen specifics do the trick to set the scene without overload. Shuffled, gurgled, dark roast, chipped blue, twisted, gulped — all of these draw a nice little picture for us, one incorporating setting, character, and tone, not to mention the clear presentation of conflict. It's a much better passage for the reader to read.
Yet, the first example ("tell") can nevertheless be appropriate to use when a particular scene is unimportant to the overall narrative, merely serving to get us from point A to B efficiently.
That said, better writing might use the less discussed technique of narration, which is a way to compress time/summarize events as a way to move into a specific instance that will need to be shown. Think of narration as the equivalent of a film montage. It's telling (note the lack of sensory detail) but artful.
"Mornings were always a rush for Georgia—a blur of alarms she didn’t hear, snooze buttons she slapped, and hasty cups of coffee she barely had time to drink. But today, as she glanced at the clock and saw she was already running late, the panic hit her all at once. She gulped down her coffee, grabbed her bag, and bolted for the door, hoping the day wouldn’t get any worse."
Many times, the advice to "show, don't tell" really means: write better. Not everything needs to be shown, after all. Can you imagine how tedious that would get? But we can work to tell — provide the reader with straightforward, necessary information — in interesting, immersive prose.