This reminds me, there was an interesting moment during Trump's inauguration speech. A couple of minutes in, soldiers are suddenly marched down to line up in formation behind him, as he begins the line "we are not merely transferring power from one administration to another...". Then, just as he begins the line "for too long a small group in our nation's capitol..." the soldier in charge marches up behind them, gives them all an order individually, and they make a show of marching away.
It was described as "mysterious inauguration misstep by soldiers" in the press, and no explanation was ever given.