Queen Elizabeth shared a moment with a passerby after dropping into her cousin's Notting Hill home to celebrate her birthday.
Her Majesty had the brief encounter on Thursday while leaving the home of Lady Elizabeth Anson, who turned 78 the next day.
The sudden appearance of the monarch in a bright green dress left one resident of the north London borough in shock.
"I never thought I'd see Her Majesty hanging out in my "hood"," they told The Daily Mail.
"She looked at me and gave me a friendly smile. I felt like this was a movie, when the monarch suddenly turns up on your street and gives you a warm look.
"It was funny how the security with her said, "Please, stand back," as there was only me — so I just took one step back."
The Queen's visit to her beloved cousin came at the end of a busy week.
The 93-year-old spent three days playing official host to Donald Trump during his state visit.
After making sure the American President had a regal visit, Her Majesty attended D-Day commemorations in Portsmouth.
While the Queen didn't have to travel more than a couple of miles to get to Notting Hill from Buckingham Palace, the two north London spots used to be miles apart in terms of perceived class.
Home of the famous carnival that takes it name, Notting Hill used to be considered a rough part of the capital.
It is now one of London's most expensive and exclusive areas.
