Personally, I'm not convinced of any shape to be determined from what are obviously short focal-length cameras on the Virgin craft. Face it, the cameras are not there for science, they are there to provide shiny publicity images for the Virgin operation. You are always going to get this when the camera is attached to the device it is photographing. The image from Felix Baumgartner's capsule is another example.
Having said that, the FE cause is hardly advanced by Pete giving us 3 screenshots from at least 2 different cameras, taken at airliner-altitude and purporting to show concavity (unless, of course, he is just seeking to demonstrate the futility of our attempting to draw such conclusions).
On the other hand, the RE cause is not advanced by making unsubstantiated claims about what we think the craft passengers saw through the enormous windows.