When I spotted her, she was framed by a work more brutal and beautiful and even more truthful than the one I had found. It was painted by a master called Niccolò di Pietro Gerini, a Florentine working in the fourteenth century. Against a featureless gold background, it depicted a young man who was very beautiful but bluntly dead, supported bodily

These paintings taught me about attention and duration, and that what I’ll see depends on how I look, and for how long. It’s a lot like breathing.