While juxtaposition might most commonly mean physical contrast, we can also use description and narration to contrast non-physical features, such as personality, attitude, or behaviour.
One's keen and invasive, kind of entitled; the other is reserved, likes to mind their own business.
How does Sharon M. Draper use contrast to highlight the difference between Gerald's mother and his nurse in this next snippet?
A pretty black lady walked into the room then, and at first, Gerald thought it was Mama. But Mama never, never wore white, and this lady was smiling and Gerald knew that when Mama came to get him, she’d be screamin’ and yellin’ and cussin’.
(There's also the contrast of wearing white vs never, never wearing white.)
Notice how in this snippet, the two characters aren't literally in the scene together. Gerald is comparing them in his mind.
Here are a couple of examples that contrast character personalities and attitudes:
Jakob was the kind of old fisherman who had had enough brushes with death to now be cautious whenever a new or strange situation presented itself, whereas Mika was all giggles, pokes, and grinning selfies.
Ivan was the good jock type. Calm, confident, relaxed. He found maths easy and never got flustered. Ainsley was all about drama. Her eyes and fingers were always darting about, she talked at double speed, and she was always in a conflict with someone or other, at work, school, even just ordering fast food.
You can approach this as static description, as in the examples, or you can put the characters into action, as in the source snippet.
Continuing the theme of personality, how can we use contrast to define the relationship between characters?
