Great spot! I totally agree that helps the "it's the lighting" argument. What still puzzles me though, is why would they change what they're doing? All the QC pics since the very beginning look to be taken on the same table in the same room with relatively the same lighting. And no one had a problem with the pics. It would be dumb for them to change their photographic methods or adjust the pictures to make them look worse. "If it ain't broke, don't fix it!"
Outside of applying a filter (which could have been related to different camera operators), I would think it more has to do with the time of day when the pictures were taken. There very well could be a window to the left of the table. So, they actually didn't change anything about how they do the photos, and yet there is a difference perceived.