Starting in macOS 10.13 Ventura and iOS 16, Apple now offers the ability to have a Shared Library that allows multiple people to contribute to a single shared library that is synced via iCloud Photos to all of their devices. If you have the Shared Library feature enabled in Photos’ preferences, all of your photos will either be in your personal library (accessible to only you) or your shared library (accessible to other users who share the same library).
In Photos, you will see a menu at the top of the window that lets you switch between viewing just your personal library, just your shared library, or the contents of both libraries combined together. In PowerPhotos (and any other third party app), you will always see the combined contents of both libraries when browsing through your photos. Apple doesn’t provide a way for PowerPhotos to tell which photos are from the personal library and which are from the shared library, so you will need to view your library in Photos to see that information.
Whenever you use PowerPhotos to import, copy, or merge photos into your system library when you have the shared library enabled, those photos will always be imported into your personal library, and not the shared library. After photos have been added to the personal library, if you want to move them to the shared library, you can open up Photos, select and control-click the photos you want to move, and select the “Move to Shared Library” menu item.
Note that all of this only applies to your system library, and only if you have both iCloud Photos and Shared Library enabled in the Photos preferences window. Any other libraries you have set up in PowerPhotos act as libraries that are local to your Mac and don’t interact with iCloud at all.
Known Photos bug when duplicating a library As of the initial release of macOS Ventura, there is a bug that you may encounter if you make a duplicate copy of your system library while Shared Library is enabled, either using the Finder or the Duplicate Library command in PowerPhotos.
If you open up the new copy of the library in Photos, it will still show the controls for switching between your shared and personal library up at the top of the Photos window. However, despite the presence of these controls, the copy of the library is not connected to iCloud Photos or your Shared Library at all. You can even use the menu commands in Photos to move photos between the personal and shared sections of the library, but those changes will not sync to iCloud and will not appear in the actual shared library for any users.