Amelie Bowen and a friend were filming a dance video for TikTok in her bedroom on Wednesday when Ms. Bowen’s mother entered the room to deliver sad news. Liam Payne, former member of the boy band One Direction, had died.

Ms. Bowen, an 18-year-old student in Redding, England, who has been a fan of the group since she was 4, was shocked. She and her friend initially started laughing in disbelief. It took a few moments for what her mother was saying to register — especially given that Ms. Bowen had been mid-dance with a face of “pirate clown” makeup her friend had put on her as a joke.

Ms. Bowen caught the moment on video and later uploaded it to TikTok, where it has been viewed more than 3.7 million times. (Ms. Bowen has just over 2,000 followers.)

The impulse to post the recording felt natural, she said in an interview: “I’m constantly filming.”

Her video was just one of several that gained traction on the platform in which users have captured their apparent reactions to news of Mr. Payne’s death. In one, workplace security footage shows someone finding out over the phone; in another, a musician who was livestreaming when the news broke abruptly ends a song and shows viewers that she is shaking. Other users filmed themselves telling friends.

In the early days of social media, most users tried to curate slices of their lives to create an aspirational version of themselves. But more recently, users on platforms like Instagram and TikTok — many of them members of Gen Z — have been willing to show their followers much more unvarnished, and sometimes dark, moments, or have been capturing them by accident.