The action of a user capturing an image or video of content displayed within Instagram Stories, using the device’s built-in screenshot function, does not generate a notification to the original poster of the story. For example, if a viewer uses their phone to take a picture of a story, the story’s owner will remain unaware of this action.
This functionality, or lack thereof, is important due to privacy considerations. Users might want to document stories for personal reference without alerting the content creator. Historically, Instagram experimented with notifying users of screenshots, but this feature was discontinued, likely due to negative user feedback and concerns surrounding privacy expectations.