Britain's tallest policeman was among the officers standing guard outside the hospital in which the Queen spent the night.
PC Anthony Wallyn, who is 7ft 2in (2.18 metres) tall, was stationed alongside the smallest officer in the Met's Westminster Borough Support Unit, PC Tony Thich, who is 5ft 6in (1.67 metres).
The pair, known by their colleagues as Big Tone and Little Tone, stood at the entrance of King Edward VII's Hospital in London on Sunday while the Queen received treatment there for a stomach bug.
She was discharged from the hospital on Monday afternoon - 24 hours after being admitted.
PC Wallyn, whose nicknames include Big Tower, has required a custom-made uniform since joining the force four years ago.
The father-of-one, who wears size 17 shoes, said: "I get 100-500 requests for a photo each day.
"It's like being famous but without the money.
"It's happened every day of my life. If it didn't happen I would be worried."
PC Wallyn said it would make for an unusual image if the Queen - who is 5ft 4in (1.62 metres) tall - had walked past him when she left hospital.
"It would be a nice photo," he quipped.