Pretty sure that is most simply explained by prominence on a supermarket shelf. Something short and stubby is hard to see so people don't buy it, which is true

Pretty sure that is most simply explained by prominence on a supermarket shelf. Something short and stubby is hard to see so people don't buy it, which is true in general, not just for capers. That's why you only really see that form factor on things like free sample jars and one shot jam jars that go into airplane meals, hotel buffet breakfasts etc- things where the manufacturer isn't fighting for prominence with other brands. That theory is also supported by the fact that big caper jars typically have the same aspect ratio as jars of other things (ie they aren't just a scaled up version of a small caper jar). At that size they have enough prominence on the shelf.