“For younger people, the thumbs-up emoji is used to be really passive-aggressive,” a 24-year-old Redditor wrote. “It’s super rude if someone just sends you a thumbs up,” they added.

To Gen Z, that classic smiley face emoji isn’t all sunshine — it’s more of a smug, side-eye smirk that can come off as passive-aggressive in texts like above. “Emoji use may be related to ...