Except the factcheck photos are much higher quality (contrary to the red herring posted early in the thread which is not from factcheck). The other difference is that factcheck photos are photos of a modern document which is a little easier to forge (being created with modern equipment). This photo is a photo of an old document that would be harder to forge and so a forgery will be easier to detect (just like Rathergate).
They higher quality images were pulled from FactChuck and replaced with lower resolution images as soon as Polarik started taking a close look at them.
But you already knew that didn't you?