A profile photo can be managed both by the employee themselves and by users who have permission to update employees.
Your own photo, as an employee
You can upload and remove your own photo from your profile page.
An employee's photo, as an authorised user
You can add a photo in two places: on the form that opens when you add a new employee, or from the employee's profile record. You can remove an existing photo from the same place.
Downloading photos in bulk
There is no way to download every employee's profile photo at once. You can, however, download all the files one employee uploaded in the document approval area with the Download All button.