From what I’ve heard the picture was taken by one of the footplate crew who got down from the loco to confront these people after the train had been brought to a halt because of the mass trespassing. Numerous other non-steam trains were delayed because of this incident. It’s a sad story as it is now quite likely that Flying Scotsman will be banned from the mainline after many instances of trespass. From a railfan point of view it is a relief that only this loco attracts mass trespass and there’s been no public suggestion that mainline steam will be banned more generally.
Best wishes,
James