What a nice day to shot! I like the foggy weathers because the fog can diffuse the light that makes it look softer (the lights in the background are the traffic lights and the street light). Usually it should be really bright to give people cautious and brightness; however, in this case, both of the light source got soften.
I used cotton for the word soft is because cotton is used in many soft things such as pillows, sofas etc. (and it is used to soften things). Photo from Swamibu: http://www.flickr.com/photos/swamibu/303860018/in/photostream/