Burger King is the latest brand to spark criticism on social media with an ad depicting diners struggling to eat western food with chopsticks.The fast-food chain showed a video clip of diners trying to eat its new “Vietnamese Sweet Chilli Tendercrisp Burger” with large red chopsticks. Social media users say the ad, which was posted on Instagram, is culturally insensitive and plays to stereotypes. It included the caption: “Take your taste buds all the way to Ho Chi Minh City.