A man and a woman are lying face down on the grass. Their heads are covered with what looks like a plain white T-shirt. Fully naked, they are engaged in some sort of fight — an arm wrestle — in which no one triumphs.Onlookers never know who wins as it’s a video playing in loop for two minutes — an artwork by Thai artist Tada Hengsapkul on view at the recent S.E.A. Focus 2020, which was held last month at Gillman Barracks visual arts precinct in Singapore.“It’s a living monument,” Tada said of his artwork. “It’s a never-ending fight between women and men. Or it can also be interpreted different…