WASHINGTON (NYTIMES) - It was a pleasant 30 deg C or so in Plains, Georgia, when United States President Joe Biden and his wife Jill visited former president Jimmy Carter and his wife Rosalynn at their home on April 29.
Mrs Biden wore a dress covered in lemons and two delicate silver bracelets. Mrs Carter was dressed more casually in a white long-sleeved T-shirt, sneakers and a smartwatch. Mr Biden wore a royal-blue suit, and Mr Carter a sport coat over a T-shirt.
"We just had a nice time," the current president said later.
Reporters were not permitted inside, but a photo of the two couples that the Carter Centre posted on Monday (May 3) on Twitter - with its toothy grins and teacups - seemed to back this up.
Except one thing was off: At some point during the visit, the Bidens appeared to have turned into giants.
Mrs Biden is 5ft 6 (167cm). So far as the world knows. Mr Carter, 96, stood around 5ft 10 (178cm) at his tallest. But even kneeling, she appeared to dwarf him. And Mr Biden, who is 6ft tall (182cm), seemed to hover above the man he had come to pay his respects to. It was as if the hosts had been turned into Hobbits.
"Did they pull some Gandalf/Hobbit perspective trickery or are the Bidens actually this gigantic?" one man asked on Twitter. Another user asked if she was "the only one who thinks this looks like a tiny doll museum, and Joe and Jill are giants?"
In a thread on Reddit that was full of Hobbit jokes, others countered that perhaps age had shrunk the former president to 3ft. Or maybe, some wondered, there was something going on with the lens. So which is it?
Reached by phone, chief official White House photographer Adam Schultz confirmed that he took the photo but declined to explain. "It's for people to figure out and think about," he said.
The answer can be found in Mr Carter's gigantic shoes, said Mr Pete Souza, a former chief official White House photographer for president Barack Obama. Compared to the rest of him, they look huge.
"That to me is an indication that the foreground was distorted by a super-wide-angle lens," he said.
Such lenses can be helpful when a photographer is trying to shoot several people in a small room and cannot get far back enough to get everyone in the same frame with another lens. But they are notorious for distorting proportions, Mr Souza said.
Mr Jaron Schneider, the editor-in-chief of PetaPixel, a photography and camera news website, had a similar theory. "It's called perspective distortion," he said.
Wide-angle lenses make objects closer to the camera appear to be much larger than objects that are even just a tiny bit farther away.
Because the Carters are leaning back, the wide-angle lens exaggerates the few inches between them and the Bidens, Mr Schneider said. Had the Bidens and Carters been seated on exactly the same plane, this effect would not have been so striking. This is why the two men's shoes seem to be on a similar scale.
The placement of the chairs also exacerbates the distortion, he said. The centre of a wide-angle photo tends to look natural. But once you start moving toward the edge of the photo, the proportions get increasingly distorted. Had everyone been huddled around the lamp, the effect would not have been so noticeable.
"Wide-angle lenses have this angle no matter how optically correct they," Mr Schneider said, adding that these sorts of optical distortions can be fixed in post production.
But while editing the photo may have made it look more realistic, that would be frowned upon, said Mr Doug Mills, a photographer assigned to the Washington bureau of The New York Times.
Mr Mills was outside the Carters' home during the photo session and saw the flash go off inside. He agreed that it seemed likely that a wide-angle lens was used to solve the problem of capturing all four subjects in a small space. Some asked why the Carter Centre would release a distorted photo, or why it was not edited to remove the distortion.
"That would be completely forbidden," Mr Mills said. Official White House photographers are supposed to abide by ethical rules similar to those followed by photojournalists, he said.
The picture, for all its amusing flaws, is history.