As his long-delayed exhibition at the Saatchi Gallery - the largest solo museum exhibition to date for the French artist - opens this week, JR tells us the stories behind some of his iconic pictures. Migrants, Mayra, Picnic across the Border, Tecate, Mexico U.S.A., 2017 (above) ‘This project was at the border of Mexico and the US. We wanted to host a big picnic lunch to celebrate the installation of [my large-scale artwork of] the kid looking.