The value will always be 2 unless the ViewSize is less than or equal to 1x1, which doesn’t make any sense. It must be a mistake, I cant think of any reason why you would want to do that.
As nnerl1n mentioned above, they were likely meaning to use a Normalize node between the ViewSize and Ceil but forgot to add it. This way makes a little bit more sense, but is still an odd way of finding a multiplier for line thickness.
Either use a normalize or just a constant, or even ignore all of it and double the input scalar value. =)