This shows how the paranoia of a few idiotic individuals manifests itself as attacks on personal liberties - the very values the so-called ‘anti-terrorism’ laws were meant to protect.
Unfortunately, this ‘political correctness’ always seems to trump common sense.
Not only in Scotland and not just recently

“…..according to the Association of Chief Police Officers, the law is straightforward. “Police officers may not prevent someone from taking a photograph in public unless they suspect criminal or terrorist intent. Their powers are strictly regulated by law and once an image has been recorded, the police have no power to delete or confiscate it without a court order. This applies equally to members of the media seeking to record images, who do not need a permit to photograph or film in public places,”

When it comes to private property (e.g. the shopping centre in question), they can request that photographs are not taken, but they cannot detain photographers, demand to see pictures or demand images are deleted.

Know your rights! Great resource here:
photographernotaterrorist.org/