Due to various technical limitations on what’s possible with the Photos app, there are some types of items and pieces of information that cannot be copied between libraries by PowerPhotos. Below is a summary of what can and cannot be copied, and some caveats that apply to certain types of items.
Fully supported: photos and movies, keeping keywords, descriptions, titles, dates and favorites intact; albums, folders, and moments.
Partially supported: locations, smart albums, original vs. edited version of a photo, bursts, live photos.
Not supported: reversable photo edits, manually assigned locations, faces, and projects.
Photos and movies with basic metadata: Photos and movies can both be copied from one library to another. In addition, PowerPhotos will also copy each photo's keywords, description, title, date, and favorite status over to the new library.
Albums and folders: Both albums and folders will be copied between libraries, and populated with the same photos that they contained in the original library.
Smart albums: A smart album cannot be recreated with its rules intact when copying between libraries. If you copy a smart album, all of the photos in that smart album will be copied to the destination library, and a regular album will be created and populated with those photos.
Original and edited versions of photos: When you edit a photo in Photos, it actually keeps around two copies of the photo: the unedited original, and a new JPG version that contains your edits. This allows you to later discard your edits and revert to the original version of the photo if you wish.
Due to technical limitations with Photos, it’s not possible for PowerPhotos to copy both versions of the photo across to another library, such that you can revert the photo just like you can in the original library. PowerPhotos instead offers you the choice of which of the two you want to copy. For album/photo copying, this is located in the preferences window, and for merging, this is located in the options section when setting up a merge.
If you choose to copy the unedited original, then your edits from the original library will not be transferred, and just the original photo will be copied. If you choose to copy the edited JPG, then only the edited version of the photo will be transferred. This setting will make no difference for any photos that have not been edited, since there is only one copy of the photo in that case. The original versions of movie files will always be copied regardless of the setting you have chosen.
Bursts: If you have used burst mode on your iPhone to take a series of photos that is shown by Photos as a single burst, only the "selected" photo for that burst is made available by Photos and can be copied to another library. Additionally, if you have split a burst apart into individual photos and then copy them to another library, Photos will automatically regroup them into a burst in the destination library.
Live photos: when copying “live” photos that were taken on an iPhone 6s or later to another library, only the photo itself will be copied, without the short video clip that accompanies it.
Locations: Geographic locations can be assigned to your photos in two ways: either automatically by your camera/phone when you take the photo (embedded in the photo’s EXIF data), or manually, by assigning a location to photos using the Info window in Photos. Photos does not support assigning locations programatically, so only those photos that have locations in their metadata will have their locations preserved when copying between libraries using PowerPhotos.
Faces: Photos does not support assigning face names programatically, so any faces identification that has been performed will not be preserved when copying between libraries with PowerPhotos.
Projects: Photos projects such as books, calendars, and slideshows cannot be copied between libraries.