I am running macOS El Capitan 10.11.5, and in Photos I am unable to add a face. When I go open the ‘Info’ window, I do not get the option to add a face.
I can only add a description or a keyword, and assign a location, but not add a face.
Some faces have been automatically detected, including objects like car wheels, but several faces have been ignored. Any help would be appreciated.
You have to blow up the photo to add Faces to them. Just double-click the photo, and ⊕ Add Faces will appear in the Info panel between Add Keyword and Assign a Location.