"I love a picture that surprises you: you try to get everything perfect, then somehow it ends up looking wrong. That's why I love this one. It was taken with a Polaroid, one of those beautiful things that no longer exist. The light has caused the blurriness, giving the shot extra emotion. There's something eerie about it, too: the girl's expression is both vulnerable and strong."One of my favourites, Ellen von Unwerth talks to the Guardian about her best shot. Lovely! Read more here.