What did Donald Trump do today?

He stormed out in the middle of a photo opportunity with the President of Argentina.

Towards the end of his ultra-brief trip to the G20 summit in Buenos Aires, Trump appeared on stage for photographs with Argentina's president, Mauricio Macri. After smiling for the cameras and shaking Macri's hand, Trump abruptly turned and stalked offstage, ignoring Macri and a staffer who chased after him.

As the assembled press corps broke into surprised laughter, Trump can be heard saying "Get me out of here."

There are two possible explanations. One is that Trump simply got confused about his stage directions. If so, it's happening fairly often. Among other such "senior moments," Trump found himself similarly bewildered while traveling in Israel, Poland, and while trying to find the limousine that was parked directly in front of his exit from Air Force One.

The other is that he had another attack of the sudden camera-shyness that afflicted him a few days earlier, when he abruptly and without explanation left the White House Christmas tree lighting ceremony. Trump had apparently just received word of the Michael Cohen guilty plea that was announced the following morning, leading some to speculate that he was suffering from a panic attack.

Trump was scheduled to give a press conference right after the aborted photo op, but it was canceled—supposedly out of "respect" for the family of recently deceased President George H.W. Bush.

Who cares?

• It's bad if a President isn't up to performing simple tasks, regardless of whether the reason is mental, physical, or emotional exhaustion.