Franken is looking over his shoulder and both of his hands are...occupied. So who took the picture? Inquiring minds, etc.
In her account, she says it was an authorized and official photographer (otherwise, would not have been on the C-130) who gave her a CD with that image and all the other images from the trip on it.
She didn’t see the image until much later, apparently.
That is why nobody is challenging the authenticity of the photo.