I have to disagree
I think that the tube was filed to pressure with the folds in the tube. I think the tube wasn't placed in the tire as flat as possible, when air was put in the kink could not expand horizontally and this kink was created as the tube pushed it vertically against the rim and tire. if you look at the two folds you can see that there are other unnatural lines on the tube as well. They line up with the kink and kind of spiral around the tube like the threads of a screw Talcum would help for sure, reducing the friction between tube and tire.