This cheerfully laughing boy with sparkly eyes and dishevelled hair is not a portrait, but a ‘tronie’ – a study of a laughing child. Laughing figures are unusual, as laughter is one of the most difficult expressions to capture. The virtuoso Hals painted the boy very directly and spontaneously, using remarkably loose brushstrokes. And yet he knew exactly what he was doing. The bridge of the boy’s nose, for example, is painted with a single well-placed stroke of white.