Pictures on the left are the original shot and on the right the cropped image; I merely moved the glass slightly to reposition it over the light.  You can see the difference in blurring
(or diffusing) the light and having the light in focus.  What saved me with the light in focus was having the flake over a dark area.  Having the flake farther from the light source is
better in order to blur the light; and intense light doesn't necessarily produce a good snowflake image as shown in the top picture.