By Chiara Fiorillo Prince Harry and Meghan Markle were showing their “unity” as a couple when they attended the premiere of a new film about Bob Marley in Jamaica this week, a body language expert has said. The Duke and Duchess of Sussex made a surprise trip to Kingston and were photographed with Jamaican prime minister Andrew Holness at the screening of the film celebrating the late reggae singer’s life. They also posed with Jamaica’s minister of legal and constitutional affairs, Marlene Malahoo Forte and took pictures with Paramount Pictures chief executive Brian Robbins at the Carib 5 cinem…