SOLVED: How to Change You User Picture in Windows Server 2012

The short answer is, you can’t.  The long answer is you can if you want to turn on the ‘Desktop Experience’ feature.

Add this feature via Server Manager > Manage (link at top right of window) > Add Roles and Features > User Interfaces and Infrastructure.  Once this is added go to Change PC Settings > Personalize > Account Picture.

Enjoy!