Comment by eesmith

You must distinguish between copyright and trademark.

Andy Warhol drew images of Campbell's soup cans in paint. https://en.wikipedia.org/wiki/Campbell%27s_Soup_Cans

He controlled the copyright to that painting. That's transformative, and the result does not meaningfully affect Campbell's ability to trade.

Quoting that Wikipedia link: "Although Campbell's never pursued litigation against Warhol for his art, United States Supreme Court justices have stated that it is likely Warhol would have prevailed.", with two quotes from two Supreme Court cases.

The second such quote is from Neil Gorsuch: "Campbell's Soup seems to me an easy case because the purpose of the use for Andy Warhol was not to sell tomato soup in the supermarket...It was to induce a reaction from a viewer in a museum or in other settings."

On the other hand, were Warhol to stick his copyrighted images on a new brand of soup, that would violate trademark law as it would confuse buyers.