A conditional plus 웃기다, which is not 'laugh' (that is 웃다) but 'be funny, make people laugh'. It floats a comic hypothetical: 4D 팝콘 들고 타면 웃기겠다 'riding 4D holding popcorn would be funny', 한국분들이 보면 웃기겠네 'Koreans are going to find this funny when they see it'. 웃기다 can also mean absurd in a pointed way: 미국이 적자라 그러면 웃긴 게 'the absurd thing about calling America in deficit is…'.