How to manually add a picture to a People profile
- Launch the Photos app on your Mac.
- Select the picture that has the person’s face you want to add to a People profile.
- Click on the Info button at the top left side of the Photos window. …
- Click the Add button next to Add Faces.
For More Information Please Refer: https://www.imore.com/how-use-people-and-places-photos-mac