I see it a little differently…

To me, this looks like a forced attempt at pride. There is something to be said for holding your chin up high, but this is too much. This is the posture of somebody feeling shame, or embarrassment, but attempting to exude pride and dignity. But you can see it is unnatural, this is not the look or stance of somebody who is pleased with what has occurred.

President Trump, on the other hand, looks like somebody who is intolerant of what he has to stand next to, has no respect for them but at the same time is not worried about them, but is maintaining composure for the sake of the professionalism this situation demands.

Just my two cents.