To review, some definitions.
Scene: A scene usually dramatizes an interaction between characters, but almost always dramatizes at least one character in the moment, even if the events are part of a flashback. This is the most comment “unit” or way in which the elements of a story are expressed. Scenes tend to include both description and dialogue.
Summary: Description that is not “in the moment”. It may describe action or thought, but it doesn’t dramatize those actions or thoughts. As a result, it may seem less immediate or exciting to the reader.
Half-Scene: A snippet of scene that consists of a few lines of dialogue and description embedded into what is otherwise summary, or a different scene, as a way of deepening or providing more drama to a section of the story.
Here are examples of the differences. Note that the boundary line between these units or modes can be fluid; thus the use of “tending toward”.
Tending Toward Summary:
Crossing the street, Henry met a somewhat hairy man who wanted to know the way to the pet store. Henry was curt, and just kept on walking after he pointed the strange man in the right direction. Then something huge plucked the man off the road and Henry realized the man actually had been a giant hamster, and the thing that plucked him was a dragon.
Henry met the somewhat hairy, husky man half-way across the street, already flustered from a flat tire, the heat of the day, and now having to walk home with a big bag of groceries.
“Hi,” said the man, who seemed to have a very muscular nose, “I was wondering if you could show me the way to the pet store?”
“It’s to the left down that alley,” Henry said, without even thinking about it.
The strange man started to walk down the alley when a huge shadow flashed downward, and grabbed him up.
Henry dropped his groceries with a scream, looked up, and realized that not only had he just given directions to a huge talking hamster, but a dragon had just pulled the poor creature right up into the sky.
“Let him go!” he cried out, to the two rapidly receding dots. Even though he didn’t know the hamster at all. Was that discriminatory against dragons? he thought as he fainted dead away in the street.
Tending Toward Use of Half-Scene:
He told the police all about the dragon and the giant hamster, but they looked at him as if he were crazy. Which made him realize that if he told his wife about this, she wouldn’t believe him. She’d crinkle her ears at him, sniffle her nose and call him ridiculous. “Which is the way to the pet store, Chosen One,” he remembered the hamster saying. He also remembered the hamster smelled like sea salt and barnacles, which seemed unusual. Chosen One. Wait. The hamster had said chosen one? When the police let him go the street on the way home, Henry was still pondering that. What to tell his wife? Giant rabbits like his wife usually didn’t respond well to strange facts.