I bet they have some tool that burrows out a hole in the middle of the potato about 90% of the way from top to bottom, then they fill said hole with chili, broccoli cheddar soup, or some sour cream mix.
I bet.
If not, they should.
And, no Mr. Bread, I don't see any rough ridin' sour cream on that cart. Maybe it's a multi step/multi vendor process and you have to go to the next vendor for your fillings.
Also, I am patenting this in case this isn't what they are doing and Wendy's is reading this post. Filled potatoes are gonna be huge stateside.