Automator Service for an Auto Import Folder for Photos
This User Tip applies to Macs with macOS 10.12 or earlier versions. On High Sierra or Mojave the Automator action tends to crash.
If you want to create a folder, where you can drop photos for an automatic import to Photos, try an Automator workflow to add a folder action to the auto import folder.
Create a new Automator workflow using the "Folder Action"template:
In the title bar select the folder you want to watch for new import items. Then drag an Action "Import files into Photos" from the library of actions into the workflow.
Save the workflow with File > Save.
Run it once to add the folder action by clicking the Run button. This will produce an error message about running inside Automator. Ignore it. Quit Automator.
Now drag an image file into your folder. It should appear in Photos, if the image format is compatible with Photos.
Whenever you now add an image file to the folder you are watching, it will automatically be imported to Photos.
This user tip was generated from the following discussion: Photos app automatic sync with photos folder