Looking at this photo...it sure does look photoshopped....I know I know..lol
From someone who uses PS daily, Photoshopping was done but not for the intention of faking it. Any pro photographer, especially one taking historically relevant images will do things like clean up shadows, improve highlights, adjust saturation, etc. I can pretty much guarantee it was shot in what is known as a RAW format which retains a lot more lighting information than you would get from your standard settings and jpg output most people use. RAW allows you to adjust the images to various exposure levels, even in specific areas so if you have one area that is washed out from over exposure (such as in direct sunlight) and one area under exposed (such as in shadow) you can balance those out.
It is fairly obvious that in this image, the lighting exposure was balanced across the image of all the participants to take their faces out of shadows. Saturation was also increased on the President and VP. The color saturation of the walls was also brought down, probably to ensure the people in the room were highlighted. Compare the lighting, wall color, etc to when Beyonce and JayZ played tourist in the situation room. They get washed in the surroundings, there are harsh shadows on the walls, and the shadows in their faces are pretty deep. (of course, different cameras and flash play a large part).
One other thing that jumps out is the dark area on the right side of the main chair the general is sitting in. It is very under exposed yet when you look at almost everything else that is at the same level and angle, it isn't. That tells me they were focusing on fixing a clear exposure on the people and didn't think too much of the loss of image data due to under exposure on the chair.
I did one other thing which is put this image in PS and pull up a histogram. This tells us more than almost everything. The histogram on the top right shows you the exposure across all the color channels. You do not get an almost perfectly smooth histogram like that unless a lot of manual work was done to smooth out the exposure throughout the images. There are only two spikes on that, on the extreme of each side (over exposure probably detected on the top part of the screen grab white area- no data found because it isn't an image, and under exposure detected, probably the aforementioned black shadow of the chair).
So yes, Photoshopping was done, but it was not to deceive (just the composition and acting did that), just responsible Photoshopping a historical photographer would do for an image like this.
All of that was just said so we don't go chasing imaginary rabbits like a certain other site would.