FORMENTERA: “We’ve spent the last two years looking at the cultural identity in the Arab world from a sociological perspective,” says Mona Al-Abdallah, co-curator of “Re-composing,” an exhibition at the Palazzo Bembo in Venice dedicated to Saudi-based artists. Al-Abdallah, her sister Maya (the other co-curator of “Re-composing”) and their mother co-founded the 369 Art Gallery