Creating a new library using photos not already in Photos
In order for photos to show up in the Photos window, they must first be imported into the Photos library. If you already have a folder full of photos you want to use with Photos, just pointing Photos to the folder full of pictures won’t make it automatically recognize and be able to work with them. To make a library with the folder full of pictures, you should first make a new library in PowerPhotos, open that library, then drag the folder of photos from the Finder into Photos.