According to Stephen Frears, the Balmoral picnic is a glum episode as the Queen and family deal with the grief and notoriety resulting from the death of Princess Diana.
Having retreated to Balmoral, a glum royal family tries to find solace outdoors. When the Queen arrives at an informal hunt picnic, she notices that Prince Philip is having problems with the grill. “Those fire-lighters no good? Ask the Queen. “I brought some stew just in case. I think it’s lamb. We could always have that cold.” Like most men, The Prince insists that he’ll get it working.
Walking to the table, the Queen begins to lay out Tupperware bowls and flatware. She is deeply pensive and working mechanically, unable to come to terms with the recent death of Princess Diana and why a flag ought not be flown at half-mast over Buckingham Palace. 
Prince Philip reacts with anger, “Then I hope Robin told him there ISN’T a flag above Buckingham Palace. . . (angrily jabs coals with a long, sharp fork). . . only the Royal Standard, which flies for one reason only. To denote the presence of the Monarch. Since you’re here, the pole is bare. Which is as it should.” The Queen gives him a withering look.
Working the grill, Prince Philip tries to be comforting. “In forty-eight hours, this will have calmed down,” he says.
Driving alone while looking for Prince Philip, who is out with a hunting party. When she stalls her Land Rover in a stream, and waits for help, a powerful stag crosses her path, stops, and looks at her. If she were a hunter, the stag would have been a trophy, but it is so regal that she shoos it away “O, you are a beauty,” she says, and gathering her strength shoos the stag away. Sadly, she is later informed that the stag has been shot and killed. The moment is metaphorical, a reminder of Princess Diana’s death.
Featured Image: The Queen, Elizabeth II, (Helen Mirren) attends the picnic
The cast: Helen Mirren as The Queen; James Cromwell as Prince Philip; Alex Jennings as Prince Charles; Sylvia Sidney as The Queen Mother
See Stephen Frears. The Queen (2007). Screenplay by Peter Morgan; Peter Morgan. The Queen. Miramax, 2006