Vacation (Symbol)
One of the reasons that the British people perceive the royal family to be completely out of touch with what is going on, and to have bungled their response to Diana's death, is the fact that they do not interrupt their summer holiday in Scotland to address the tragedy. The vacation itself, which the royal family takes every year, becomes a symbol of their perceived heartlessness, a representation of their refusal to show their cards. The public sees the trip as a disrespectful sign of indifference to the memory of Diana.
Diana Herself (Symbol)
Diana Spencer was a real woman, with real ties to and real conflicts with the royal family. These ties and conflicts, however, were not simply literal, but also became symbolic, particularly around the time of her death. The film dramatizes this dynamic by showing the ways that Diana touched normal citizens' hearts, and examining the ways that she made it very publicly clear that she felt slighted by the royal family. As "the people's princess," Diana represented someone within the monarchy who both suffered under and spoke out against royal attachments to tradition and royal elitism. For the British people in the film, she represents a more modern ruler, someone who is as warm and expressive as they are powerful. In this way, she is the antithesis of the queen, who is defined by her unemotional attitude and imperiousness.
Cherie's Shallow Curtsy (Symbol)
In the beginning of the film, the queen's advisor Robin notes that Tony Blair's wife always does a very shallow curtsy when she sees her, which would suggest that she feel irreverent towards royal etiquette. When the queen meets the prime minister's wife again, having discussed this, she cannot help but notice that the curtsy is indeed shallow. Thus, the curtsy is a symbol of the fact that Cherie (and by extension, Tony) do not have very traditional values, favoring their progressive ideas over reverence for the monarchy.
Flowers (Symbol)
When she finally cedes to the public's desires and goes to visit her public, the queen is disheartened to see that many of the cards that are left in front of the palace are disparaging towards the royal family. She worries that she has completely lost the love of her public, and that she is simply reviled by her people. Then, a little girl hands her a bouquet of flowers, which the queen assumes are for the memorial for Diana. The girl tells her that the flowers are actually for her, and the queen smiles, seemingly comforted by this gesture. In this moment, the flowers symbolize the fact that the queen has not fallen out of favor, that she receives some love and admiration from the British people.
The Stag (Symbol)
The stag is probably the most important and striking symbol in the film. While in Scotland, Prince Philip spends his days hunting, stalking a very beautiful stag in the vicinity. The stag is a highly coveted kill. Elizabeth asks Philip about his progress with the stag several times. Then, one day, when she is struggling against the public pressure to return to England, she gets her car stuck in a river, and sits on the side of it weeping. Suddenly, the stag appears, and she looks at it, before urging it to run away before it gets killed. Then, after it has been killed, the queen goes to look at the body, and seems saddened to see that it has been conquered. While the meaning of the stag as a symbol is not explicit, it is directly related to the queen's sense of herself, and her own vulnerability. She has a special connection with the stag, as revealed in her moment of looking at it by the river, but she must keep her affinity for the stag private. The stag's death coincides exactly with the timing of her deciding to go back to England after all and pay her respects to Diana and the British people. Just as the stag is conquered, so too is the queen. They are both regal beings that are the victims of thoughtless attacks.
In another light, the stag can also be seen to represent Diana, a victim of thoughtless attacks. Interpreted in this way, the queen's interactions with the stag represents the fact that, although she would like to be able to publicly sympathize with her ex-daughter-in-law's plight, she is unable to show any kind of vulnerability because of the expectations placed on her as the queen of England.