So let's take a look back ... Obama once again nodded his head in what almost appeared to be a bow while greeting Chinese President Hu Jintao at a Nuclear Security Summit in Washington. Photos ...

That moment, captured by White House photographer Pete Souza, shows Obama bowing his head to Jacob Philadelphia ... It’s one of the most iconic pictures of Obama’s legacy in the White ...

Pete Souza/The White House In the first photograph, President Barack Obama is sitting in the back of the Situation ... positioned almost perfectly above his head. Mr. Trump had also just returned ...