The Queen works with very small hand signals. There is an inexplicable seven minute gap when the Queen just stands there waiting for the Trumps. This was the time when she should have inspected the troops. But she wanted to do it with the President. This is not in the protocol, and she could not announce her intentions forehand, hence the seven minute gap.
The President was just as unprepared for this as everybody else, so he bungled a couple of steps, and got ahead of the Queen once, but he followed her signals as best he could.
(A corollary is when then President Obama gave a toast to the Queen at a state dinner he paused in the middle of the toast. The Queen gave the signal to start “God Save the Queen”. Oblivious as always, Obama continued his toast and Queen Elizabeth snared: “Put it down”. https://lenbilen.com/2012/02/09/obamas-toast-to-the-queen-he-is-toast-a-limerick/ )
This is how to do diplomacy if you are the Queen, subtle but magnificent.
Len Bilén's blog, a blog about faith, politics and the environment. 