Google is making it easier to hide your embarrassing photos from friends and family with access to your phone by rolling out its Pixel-exclusive Google Photos Locked Folder feature to non-Pixel handsets.
Google Photos Locked Folder lets you move photos and videos to your Locked Folder where they can only be accessed with your fingerprint or PIN. On Pixels, the Google Camera app features a Locked Folder button which saves photos and videos directly to the Locked Folder. The media are also not available to other apps on your device and are also not backed up to the cloud.
The feature came to Pixels in June, and has now shown up on various but not all Samsung, Oppo and OnePlus handsets. See if it is available to you by checking the Library tab in Photos, then selecting the Utilities page.