Slate's Julia Turner spoke with photojournalist Scout Tufankjian about the photo of Barack and Michelle Obama that has become the most retweeted ever. The photo was taken August 15 in Dubuque, Iowa, in the middle of a bus tour.

"It was the first day that the first lady had joined us so he hadn’t seen her in a couple of days. She came in on a bus that morning -- it was the first event of the day -- and they embraced on stage," Tufankjian said. "I decided to focus on them rather than taking a wider shot, because I think I’m not alone in finding their relationship to be totally aspirational."

Photo by Scout Tufankjian

After the campaign tweeted the photo Tuesday night, with the message "four more years," Poynter's Kenny Irby said:

The Obama machine understood both the closeness of the race and the power of his image ... It was not about what the event was, but rather who was in the image. Millions only cared to see the unity of the first couple and the victory associated with that.

Tufankjian told Slate:

It reflects on the way that people feel about the Obamas as people, rather than as public figures. The wonderful thing about working for the campaign is not being with the president or on Air Force One or any of the things that would happen covering any president’s campaign. Spending time with that family is the thing that’s so wonderful. What the family is and represents to the country is as much a part of the president’s appeal as his policies.

I don’t know why they chose it, but that’s why I like the choice. As opposed to him waving in front of a flag or something more traditionally presidential.

The same moment was captured by Jim Watson for Getty.