The difference becomes apparent when considering soda pop bottle versus a high-end dress shirt. The soda-pop bottle is a trivial purchase, and is generally available among many other brands offering the same thing. However, the shirt may be purchased with more effort and care, and is generally available among other clothing from the same brand.
The brand on the bottle offers identification of the individual item during purchase and later during selection for drinking. No matter if it is found in a bin among bottles from other brands, or within a section containing only bottles from one brand. Bottles are also discarded after use, so they are not identified individually, but merely as one of many copies. I have several bottles of soda pop, some Coke some Pepsi. The brand is still very relevant.
A shirt on the other hand is probably accompanied by an entire section of clothing for the same brand, and does not need individual identification. Even more so during selection for use, shirts are generally owned by a single person and cared for individually. I only have one pink broadcloth shirt, and it happens to be from Banana Republic. The brand is not as relevant.