They likely have not created a mask of a known person that's simultaneously thin enough to not appear as a fatter version, and accurate enough to appear similar to the person it is supposed to mimic, while simultaneously, being flexible enough to fold like skin, able to sweat, it would need a new pour system. Here is an easy method to prove a mask is worn. Next public appearance, bring an IR camera. If he is wearing a mask there should be a clear heat anomaly.