That's because better than some enlisted might, the Vice Admiral KNOWS that the President is his boss. We think of him as their CinC. To him, he really is the "Boss" - with a capital "B"!!!
That's why the ADM took the camera and snapped the picture.
I've also learned from being around top brass in the US Navy, that the higher the rank, the bigger the man. There just isn't any pettiness when you've reach the rank of Captain. And if there is some flaw in your character, and you are made Captain, trust me when I tell you that their peers and their superior officers will zero in on that failing, and they'll either knock it out of him, or he won't make Admiral!
I watched the career of a CDR - a Commander, who I thought, "Man, if he makes Admiral, I'm never going to respect that rank again." He had favorites among certain enlisted, and certain Officers, and to others, he acted like the snipey, small man he was.
Well, he made it to Captain, but there, his career ended. He never made it to Admiral, and I know there were those who wondered on how earth he made it to Captain! I happen to have been among that group. I think he never should have made it to Captain but he bamboozled somebody to make it that far. Ultimately the real man shown through, and his upward career path stalled.
Sorry - more information than you probably wanted or needed.
I'm glad you posted it--very interesting.