You fill the space so that in a screen with 20 of those cards, they all have the same visual weight, no random dispersed white blocks. The purpose of the pictur

You fill the space so that in a screen with 20 of those cards, they all have the same visual weight, no random dispersed white blocks. The purpose of the picture at this point is decoration to identify a product type, not showing you details of the guitar - you'd see that once you open the product page. Your comment is like complaining that an A3 poster for a TV show doesn't show the full scene.