Due to the huge diversity in tastes, social norms, and financial capabilities, products are often sold in multiple variations. A refrigerator could be sold in three or four sizes and in even more colors. Visually focused products like clothing, carpets, curtains, and cosmetics like lipstick are often offered in hundreds of colors.

This brings us to product images. Generally, a refrigerator that is 70 inches tall doesn’t look very different from one that is 80 inches tall (at least in pictures) but a white refrigerator is quite distinct when compared to a pink or lime green one. So, when a customer chooses a certain color variation, you need to display images of products in that color.

Let’s say Jonah comes in to buy a t-shirt. The default image shows a blue t-shirt but Jonah wants his in black so he selects that color variation. When this happens, you need to show Jonah the same t-shirt, but in black. You can’t just continue displaying the same images of a blue t-shirt and assume that he will visualize how a black t-shirt looks in his head.

That would be terrible for user experience on two fronts:

• First, it’s too mentally taxing. Buying should be a seamless experience, not an exercise in mental image creation. A customer shouldn’t have to think about what a product looks like. Show him. 
• Secondly, Jonah is bound to assume that the t-shirt is only available in blue or that the black variation has sold out and consequently abandon his purchase.