It isn't just the Queen who can use bags for unorthodox purposes. Her former daughter-in-law Princess Diana was no stranger to strategic bag use either. In many pictures of her taken at events, she'll be seen holding a tiny clutch bag that could scarcely have contained anything useful at all. According to her former personal shopper, carrying things was never the point of them.
Diana was once the world's most photographed woman. She also broke Royal protocol by appearing in low-cut dresses and tops (just one of many things she and the Queen disagreed about). Paparazzi would routinely attempt to get pictures of her cleavage as she made her way into or out of cars, and the clutch bags were her defense against that. Held at precisely the right angle, the bag would frustrate the photographer's gaze, and result in them having a wasted trip. We can't say we have much sympathy.