It’s August, high season for New York galleries to put on their annual, all-inclusive, mega-group exhibitions. But on Mykonos, the Greek isle where models go to play, a group show feels like an exclusive retreat. It’s where 16 New York artists are seeking some sun-drenched refuge this summer in “Greek Gotham,” the country’s first exhibit exclusively of New York artists. Brooklyn names like Mira Dancy and KAWS are showing their work at the scenic Dio Horia gallery, in a show curated by art adviser and designer María Brito through the end of the month. There’s a book of the same title that Brito wrote withJeffrey Deitch, too, but the view says it all.