The words "Run, he's got a gun" reverberate in stereo from Paula and Bridgette Powers and, just like that, they're a viral sensation reaching all the way to Hollywood talk show host Jimmy Kimmel. The armed carjacking the identical twins are describing doesn't interest Kimmel, or the millions of people who watch the video of them detailing their mother's encounter with the gunman. What scores the sisters — known as the Twinnies — a spot on Kimmel's popular show is the way they relay the story. It's a mesmerising, double-barrelled delivery of the same words and sentences, often in sync,...