I have tried and failed to find a spooky photo I made like this years ago. The thing is that the light is diffused/blurred (whatever the correct term is?) into the dark areas - but because we are printing a negative it is the opposite way round to using a soft-filter or diffuser on the camera. Effectively the shadows 'eat' the light areas, if you do it to excess with a suitable contrasty neg it can look rather 'different'! :o)