Quilting is presumably done to keep loose material such as feather down in place without creating too much of a cold spot (thermal bridge) by displaced material. Modern (synthetic or natural) fill sleeping bags can be box sewn, having cloth pieces fitted to make compartments instead, with even less loss of heat.

But generally such solutions lower the insulation capability and makes no sense for sewn textiles out of hollow fiber material. Maybe we should put that down as an example of Sky’s fashion sense overpowering her sense of practicality.

OT: These view references is an exploration in psychology. I had no idea that female figures lacking arms were more bothering to my psyche than men. Go figure! …, uh, or something.

For another hypothetical example, if a character carries his gun at his waist on the side, drawing the arm in would obscure that. So I might forego the arm in order to show the gun and holster.

Or maybe I’ve just seen too many Star Wars movies and like characters with arms chopped off.