Former New York governor Mario Cuomo has, for some reason, long declined to sit for an official portrait, resulting in a sad, empty space on the wall of Albany’s Hall of Governors. So, naturally, his friends secretly commissioned an oil-on-canvas painting based on a 1989 photograph of the politician, and then they had his son, current governor Andrew Cuomo, present it to him yesterday as a belated birthday gift. According an aide present for the surprise unveiling, which took place during an Executive Mansion gathering of campaign alumni, the elder Cuomo wasn’t totally thrilled. “I didn’t want a portrait, I didn’t ask for a portrait,” he said during a brief address. However, by the end, he was willing to admit to at least “liking” the thing, because what was he supposed to say?