Queen Elizabeth II
Queen Elizabeth II paid tribute to Princess Diana after the latter's sudden death. Pictured: Queen Elizabeth II is seen at the Chichester Theatre while visiting West Sussex on Nov. 30, 2017 in Chichester, United Kingdom. Getty Images/Stuart C. Wilson

Queen Elizabeth II did a surprising gesture to pay tribute to Princess Diana.

The Queen had been criticized in the past for not flying to London right away after learning about Princess Diana's death. Queen Elizabeth II was in Balmoral Castle in Scotland with Prince William and Prince Harry when the accident happened, and it took her days to fly back to London. However, Her Majesty made a surprising gesture to honor the People's Princess.

According to People, when the Queen arrived in London, she walked among the mourners, collected well-wisher's flowers and gave a message on the eve of the funeral. On the morning of the funeral itself, Queen Elizabeth II led the family out to the gates when the cortege passed the palace and did a "completely unscripted" gesture.

"I pushed my way through the crowd, which was about 20 deep, and luckily the BBC had left a ladder against a tree. I managed to climb the ladder and I have the only shot of the Queen bowing her head at the coffin as it goes past," photographer Mark Steward told the publication. "It showed the Queen . . . The best of the Queen, really."

As for the Queen not flying to London right away, Charles Anson, a former press secretary, believed that the monarch did the right choice. For him, she did what needed to be done at that time.

"It wasn't that easy for the Queen," Anson said (via Marie Claire). "They did what any decent family would do. The first thing was to gather round those boys and give them as much protection and support as possible."

In related news, there are already talks as to what will happen when Queen Elizabeth II passes away. According to Amani Hughes, the first person who will be informed will be her private secretary, Sir Christopher Geidt. He will be the one to inform the prime minister before informing the 15 other countries of which the monarch is the head of state and the rest of the 26 Commonwealth nations.

When this happens, the market and the advertising industry will be affected. A number of networks are expected to observe this through their social media activities and advertisements.

"If the event is sombre, it will cut out advertising as it's very hard to strike the right note. And audiences don't like interruptions anyway in these ceremonies," said Alice Enders, head of research at Enders Analysis.