WhatsApp from Facebook has a feature called Delete for Everyone that lets people unsend messages, photos, and videos from an individual’s phone, or everyone in a group. But it doesn’t delete them from iPhones.
According to Shitesh Sachan, an application security consultant, who found this privacy issue and shared his findings exclusively with The Hacker News, the feature for WhatsApp for iOS has not been designed to delete received media files saved in the iPhone’s Camera Roll.