The 44th American President is much different than many of his predecessors (let’s call them pre-dinosaurs), who used all their energy and power to generate hatred and killing millions of innocents.
But Obama is 180° apart from this vile tendency.
Being an American President, one doesn’t need always to show supremacy, and be the sole Star of the events (a ‘had-to-be’ rule). There are others on the podium. During his recent meeting President Obama expressed his gentle sincerity to the Saudi King Abdullah, which had also a physical expression with polite gestures.
President Obama is well-educated and knows the culture of Middle East very well. In Japanese culture, the host bows to the guest as a gesture of warmth and friendly sign, which in fact an honour remains due for the host to be paid later. This is a custom of high-respect. President Obama knows this.