I think another reason that someone in the public eye like them may choose not to share their photos is to probably stop the public from getting a chance to gossip negatively about them. Or even misinterpret what the photo means, something that seems very innocent could be misunderstood by people. So especially in conservative Islamic communities, they choose to reduce this from happening.. and the Sheikhas have a reputation to keep ... like any human being they wouldn’t like to be misunderstood.... as Lasya described... one photo of Sheikha Shamma last year and some people didn’t approve I guess, not sure what was the reason, but I guess to avoid such incidents... anyways we don’t know if she will post public photos of herself.... on the other hand some other Shaikhas don’t mind revealing their pictures, and in Islam it is not forbidden for a woman to show her face, so even if any of them do show their face, it is not unlawful.. I guess it’s personal choice ..