Sky Shot

This photo of the Swiss A340 and United on parallel approach to KSFO was summarily rejected for being a skyshot (http://www.airplane-pictures.net/images/rejected-images/2015-7/590636.jpg):

I was referred to the guidelines - which is silent about two aircrafts in the air in the same shot. I would understand if the rejection was for a technical fault (focus, sharpness, haziness, noise, framing etc.,) rather than what appears to be ambiguous/arbitrary application of a rule that does not explicitly apply here.

Previously, such shots were accepted - United A319 and Virgin America (See http://www.airplane-pictures.net/photo/472839/n812ua-united-airlines-airbus-a319/).

This shot of the United Dreamliner at KLAX (http://www.airplane-pictures.net/photo/490991/n26909-united-airlines-boeing-787-8-dreamliner/) is described as being discretionary ... so it was easy to understand it's acceptance/rejection.

Attached photos: