When you make a BeReal account, anything you post is private by default. Only your friends can see your photos and the associated captions. However, you can change these settings and make your uploads public. When you post an image to the Discovery timeline, it will reach other BeReal users, not just your friends. They'll also be able to see the caption you've added to your post. While it's fun to share your posts publicly occasionally, the app will also display your geolocation. If you're uncomfortable with strangers knowing your approximate location, it's best to stick to the app's default settings.