I was looking around in the analytic module but it seems the photo is not part of the profile, so it does not show in that report. We have not required or suggested that folks add a photo. We have external and internal folks in the Support Community. With over 41K members, checking manually using the people search page would be a pain.
My personal take is if the employee has face-to-face interactions, they should add a photo. If you have an employee directory or a badge system where you can get the photos, a webservice could be created to auto load them.
For an internal there is a lot of searching the employee directory for photo, location, and org. If the system auto loaded those, it would increase usage.