In February 2012, President Barack Obama hosted a science fair in the White House, where he was photographed with a fourteen-year-old contributor to the fair, Joey Hudy of Phoenix, Arizona. One image of the event captured the commander in chief’s wide-eyed expression as he gleefully operated Hudy’s invention, the “Extreme Marshmallow Cannon.” This image had an afterlife, circulating on Facebook and Twitter (@karinjr, with a link to a ...