The image is dynamite. It's much more powerful than any of the classic Diana pictures, for instance, because (a) it is so politically charged, and (b) because it seems so revealing of character. When I am preparing my 'lookalike' photographs, I think about the character of the real people, because, if the photographs are going to be plausible, you have to convince the viewer that they could have happened.
So, if I'd been mocking up a fake Harry, I would probably have used some of the same 'props' that appear in the photo - the drink, the cigarette. That reminds you that he likes to party, that he's the playboy prince.
And the Nazi stuff recalls some of those historical connections that the Royal Family is not too keen on us remembering. Coincidentally, I had worked on some shots of Prince Philip for my TV show, Double Take, which we didn't use in the end but which showed him opening his wardrobe to reveal Nazi memorabilia.
Of course, you want to shock or thought provoke [Jackson first came to public attention with a Snowdon-type pastiche of Diana, Dodi and their invented baby], but you also want to suggest something we believe is possible. So, with the Harry picture, you have all the ingredients for it to be dynamite - the cigarette, the drink and then, bang in the frame, the swastika. If I'd been posing it, I couldn't have wished for more. And you have the key revelation of character, or at least how we think he is.
The picture also has that 'stolen', documentary feel that I try to achieve in my photographs or films, which I set up as if they've been taken without the subject being aware. This lets the viewers think they've gained access to something private.
This 'peep hole' feel the real Harry picture conveys brilliantly - partly because it's taken on a cheap camera. With new technology, with a small camera or mobile especially, you can 'steal' an image without anybody noticing.
The image has gone straight into the collective psyche, straight into the history books. This is now a classic image. None of us will ever forget Harry like this, will we?
· Alison Jackson, artist and photographer, won a Bafta award for her series 'Double Take', and is now working for NBC's Saturday Night Live.