Every single person in the line is not shaking his hand, which renders a mass snub as totally improbable. And the action of the president is to precede (introduce) each person the delegation to the Russian leader, who then shakes the hand. And I am not a Dem or an Obama supporter.
After reading some of the replies of some of the people in here who truly believe that BO was snubbed, the above brain hemisphere measurement makes a lot of sense!
I was going to guess that you were heavy on the left brain. Here is mine: Left Brain Dominance: (9) Right Brain Dominance: (9)