Thanks for your comments team. I’m afraid you are wrong. My research suggests that Soft Serve has less fat than ordinary Ice Cream. The real difference is the amount of air in the ice cream and the temperature at which it is stored. In my view it is the amount of air that is crucial. When Soft Served is warmed I would suggest that the air in the fat which makes up the ice cream makes the ice cream expand to a greater extent than the ordinary ice cream.
You could try a little experiment to confirm this. Take two equal samples of ice cream (soft serve and ordinary) of the same weight (use kitchen scales). Let them warm up. Allow the ordinary ice cream to reach the same temperature as the soft serve (ordinary ice cream is usually kept at a lower temperature than soft serve). Make sure that the two samples are in the same kinds of containers. Do they expand to the same degree?
What do you think the role of the air is in this process?
I hope that this gives you a clue to any differences that you see.