Smile! On Friday, the White House unveiled the president's new official portrait, taken once again by White House photographer Pete Souza. And perhaps unsurprisingly, President Obama looks a lot older after a grueling first term. "It's like they went in a time machine and fast-forwarded eight years in the span of four years," Connie Mariano, a former White House physician, tells the Denver Post.

In the 2009 portrait the president gives us only a flicker of a close-lipped smile as he poses against a drab, gray background. But his face reveals his youth: Only a few wisps of salt in his pepper-black hair; a couple faint lines of crow's feet are etched into the corner of his eyes. And perhaps because the framing gives ample space above his head, Obama kind of looks like he's ready for his first day of boarding school rather than a term as president.

Now for the 2013 portrait: The president looks older, no doubt. His hair is more gray than black. His face, despite the smile, fights the pull of gravity. And he has acquired a few more folds around the eyes. But he also seems happier and more at ease — a sense heightened by being inside the Oval Office instead of a rather blah studio. The desk and drapes give the room a warm feel that is only enhanced by the president's familiar, toothy grin. He fills the portrait with his straight-back stance, and his casually folded arms reveal a more self-assured man, the knowing senior who's lived through his fair share of all-nighters and nail-biting close calls.

What do you think? Leave your thoughts in the comments below.