The US president – whose visit was greeted by hundreds of thousands of protesters - met the monarch for tea at Windsor Castle during his first official visit to Britain last week.
Mr Trump was accused of breaking royal protocol twice within minutes of meeting the Queen by failing to bow and walking in front of Britain’s longest-reigning monarch.
A slew of theories about the Queen’s choice of various brooches during the billionaire’s working visit has now surfaced.
Eagle-eyed observers have speculated the 92-year-old royal might have been trying to show her disdain for the controversial president via her jewellery selections.
While receiving the Archbishop of Canterbury and the Grand Imam of Al-Azhar for an audience at Windsor Castle on Thursday - the day Mr Trump arrived in the UK - the Queen wore the American State Visit Brooch.
The vintage breastpin, which is a small green flower and featured 14-karat yellow gold, diamonds and moss agate, was a present from Mr Obama and Ms Obama during their state visit in 2011. The Obamas reportedly hand-picked the present at Tiny Jewel Box store in Washington DC.
Constitutional convention of course dictates the Queen must remain politically neutral at all times, but her nod to the ex-president has been seen by some as a subtle, indirect jab at Mr Trump.
The Obamas visited Britain a number of times while in office and are known to be close to both Prince William and Prince Harry.
In a series of tweets, which have been widely disseminated, one person coined a theory about all three of the brooches she opted to wear during Mr Trump's visit. The Twitter user noted that the brooch she wore to meet Mr Trump on Friday is the palm-leaf brooch which the Queen Mother wore at the state funeral for King George VI.
While the sapphire brooch she wore on Saturday was a gift from the Canadian people – who have a fraught relationship with Mr Trump - in 2017.
Mr Trump described the Queen as “so beautiful” and his meeting with her as “really something special” in a later interview with Piers Morgan on Good Morning Britain.
He said: "She is an incredible woman, she is so sharp, she is so beautiful, when I say beautiful - inside and out. I can tell you I liked her. I liked her a lot.”
Mr Trump falsely claimed that the Queen reviewed the Guard of Honour "for the first time in 70 years" during his visit to Britain.
The billionaire made the slip-up as he recounted his visit to Windsor Castle last week during a speech at the White House on Tuesday.
“We met with the Queen, who is absolutely a terrific person, where she reviewed her Honour Guard for the first time in 70 years, they tell me,” he said.
"We walked in front of the Honour Guard and that was very inspiring to see and be with her. And I think the relationship, I can truly say is a good one. But she was very, very inspiring indeed."
But many drew attention to the fact this information was wholly false. The Queen’s coronation was in June 1953 and she has been on the throne for 66 years. She has also reviewed the Guard of Honour regularly during her reign as monarch.