Samsung
Show or Hide Notifications on Always On Display auf Samsung
On Samsung phones, the Always On Display shows small icons whenever a new notification arrives, even while the rest of the screen stays off. This behavior comes from the Notifications option inside the lock screen settings and works separately from the notification panel or lock screen previews.
The icons only confirm that something happened. They show the app icon and nothing else, no sender name, no message text, no preview, regardless of whether the toggle is on or off.
Disabling this option makes sense if you check your phone in public and even a bare app icon gives away too much. It has no effect on notifications inside the pull-down shade or on the regular lock screen, since those are separate settings.
To change it, open Settings ➔ Lock screen ➔ Notifications, then use the toggle to enable or disable the icons shown on the Always On Display.
If your goal is hiding message content rather than icons, check the lock screen notification settings instead. This particular option only controls the always-on screen.