Royal commentator Richard Fitzwilliams told CNN Trump looked like "he might as well have been wandering up and down a golf course."
However, Fitzwilliams said Trump didn’t technically break protocol, but gave the impression of “dis-coordination.”
"It proves he (Trump) doesn't bother to rehearse, because he doesn't think he needs to," Fitzwilliams said.
Trump also caused a buzz when it appeared he kept the queen waiting for tea.
The 92-year-old Queen appeared to uncomfortably shift in her jacket and hat and check her watch while waiting for the Trumps.
CNN reports the Trumps were on time for tea, arriving at 5 p.m.
When Trump and First Lady Melania Trump first met the Queen at the beginning of their visit, they shook her hand, rather than bowing or curtsying -- after Queen Elizabeth offered her hand, first.
"The queen doesn't expect people to bow to her, though many choose to anyway," said CNN royal correspondent Max Foster.
Trump is the 12th U.S. president to visit the queen during her reign.
His visit has been marked with massive protests in London, including a massive Trump baby balloon.
Protesters also greeted Trump in Scotland on Saturday.
Trump spent Saturday afternoon at his golf resort, Turnberry, located in southwest Scotland.