From the Dairy Queen FAQ:
How come my Dilly Bar doesn’t have a curl in the middle?
Some Dilly bars are made by the staff of DQ stores and those have a curl. Others are manufactured for those DQ restaurants that do not have the space or the staff to make their own. Those Dilly Bars are packaged in clear plastic and do not have a curl.
The manufacturing equipment is not able to duplicate the trademark curl on our Dilly Bars. There are positives, however, to the manufacturing process. We can offer our Dilly Bars in additional flavours, including Mint and no sugar added.
I have no idea what the “curl in the middle” of a Dilly bar is, as I was never allowed a Dilly bar at Dairy Queen. But it’s nice to know we still need humans to put it there.
(There was a Dairy Queen across the street from my high school; its parking lot was the place where fights were held: “Jimmy is fighting Danny in the Dairy Queen parking lot after school, pass it on!”)