Of course, Consumer Reports, those geniuses of product testing, found no real difference in the low light performance of the IP5 & IP4S. Clearly that was wrong, so clearly there are ways to not get good low light performance that don't have so much to do with the phone as with your testing. And, there's no way to know that the phone Engadget was allowed to handle is the same as the phones Nokia will eventually ship. In this instance, one has to consider that Nokia hasn't had any qualms previously with engaging in deception, and this "prototype" phone may have components that the production models will not.
So, basically, those photos are worthless as evidence of anything. If we thought Nokia could be trusted, that would be one thing, but since we know they've been lying about these devices, and particularly about the cameras in these devices, prior to this, no one should just accept that the prototype or the photos are legitimate. (And, no Engadget are not good judges of that for us.)