I imagine she was asked to remove her head cover and she refused. In the side shot of a mugshot, the ear needs to be visible as it is a unique identifier. Removing glasses, hats or anything else is SOP.
The police should have offered her the opportunity for a female officer to take the picture while the males turned their backs (and she is handcuffed for safety reasons).
What are your thoughts on this if she was fully vailed?
What if a KKK member is arrested and refused to remove his hood?
For some Muslim women, just being touched by a strange man is haram. Religious protections are not absolute. If your religion calls for child sacrifice, the practice will not be protected.
One is expected to consider the consequences and personal contribution to the circumstances created. If you are not prepared for the potential of a mugshot, don't put yourself in a situation where it might be required.
If she assaulted an officer or even just refused to follow instructions, she subjected herself to arrest and her religious freedoms are trumped by the rights of the state to enforce the law.
I'll grant you that reasonable accomodation should be made and probably wasn't here.