Wonder how long it will last. Looks like a lot of puckering going on there.
They're actually expansion joints, I had them designed into the seat so that it reduces the stress when my weight is positioned on the seat. When I'm sitting on it, those "puckering" areas smooth right out. Just as any other properly designed engineered system you have to account for temperature and pressure variations from forces acting upon the area. These so called "puckering" areas allow the seat to conform to my buttocks area without distorting or stretching the material over time.
There's been numerous studies done on military fighter aircraft seats that are designed in the same fashion.
I'll let you know how it works out.