It looks to me like those sacks (flour probably?) are hand stacked. Certainly
maximizes the loading of the car - at the cost of labor. Soon after this photo
was taking mgmt started cutting labor costs as their most important way to
make more money. And in the days when this photo was taken it was
common for restaurants to stock flour in these quantities - and even some
homes used the bags as a way to save money (as long as you could keep
the mice and roaches out).