Just before noon on a holiday weekend, while many Americans were at the beach, President Trump’s social media account roared to life. In what has increasingly become his weekend habit, he unleashed a daylong barrage of posts that put the bully in the modern bully pulpit. There were images of Mr. Trump intimidating Canada’s prime minister with a hockey stick, personally bombing enemy targets and patrolling dark streets with killer robots. There were maps showing the United States taking over other countries, and maps renaming a state. There were attacks on the “Dumocratic Party” and tributes to himself as “the Greatest President of All Time!”

The 60 messages posted online over 10 hours and 41 minutes offered a window into Mr. Trump’s own unique reality, one anchored not in fact but in an expression of ego. For years, his social media feed was said to be a mirror of his id. But with A.I., it has become the manifestation of how he wants to be seen in a more visual, visceral way than ever before — as a warrior, as a conqueror, as a historical figure, as a younger and thinner and more muscular version of himself.

To his defenders, Mr. Trump is a master of baiting his adversaries, getting them to react. “It’s called: We do a little trolling,” as Mr. Trump once put it. The more out there the message is, the more his supporters cheer. As abnormal as the images that he posts may be for a president, Mr. Trump’s allies argue that they convey a certain raw, earthy quality that suits an age of no-holds-barred politics.

Violence is a recurring theme in Mr. Trump’s feed. He relishes the idea of himself as a tough man staring down anyone who gets in his way. He smashes Iran with a giant hammer. He pilots a spacecraft blasting the planet. Most arresting was his...