Obama gestures at Mandela memorial scrutinized

An unexpected handshake. A selfie. A seat change.

President Barack Obama's gestures at Nelson Mandela's memorial service in Johannesburg were widely scrutinized on the world's stage Tuesday.

First, Obama shook hands with Cuban President Raul Castro as the U.S. president approached the podium at the soccer stadium to address Mandela's mourners. The brief exchange, captured on video and photographs, sparked an immediate reaction online and on TV, with cable news pundits and Twitter users debating the significance of warmth shown between leaders of countries that have not had formal diplomatic relations since 1959.

The handshake also drew some sharp GOP criticism. Sen. John McCain likened it to shaking hands with Adolf Hitler.

"Why should you shake hands with somebody who's keeping Americans in prison?" McCain told Public Radio International, adding: "Neville Chamberlain shook hands with Hitler."

"This wasn't a preplanned encounter," an Obama aide told Yahoo News on Tuesday. "Above all else, today is about honoring Nelson Mandela, and that was the president's singular focus."

At another point, President Obama posed for a "selfie" from his seat at the memorial with British Prime Minister David Cameron and Denmark's Prime Minister Helle Thorning-Schmidt. First lady Michelle Obama, seated to the group's left, did not participate.

Tuesday's event was not a funeral. But that didn't stop the "Selfies at Funerals" Tumblr, which documented the aforementioned trend, from categorizing the world leaders' selfie as one.

"Obama has taken a funeral selfie," Jason Feifer, the site's creator, wrote. "So our work here is done."

"Dear Obama," Mashable's Christine Erickson wrote. "Funerals are no place for selfies."

Earlier, the first lady appeared to be less-than-thrilled with the president's conversation with Thorning-Schmidt, and at some point, she switched seats with him.

It's unclear whether the seat change occurred before or after the selfie, or if it came during Obama's speech.

Before his handshake with Castro, Obama also shared a handshake and a kiss with Brazilian President Dilma Rousseff, who has angrily condemned U.S. spying in her country.