If this was simply about rounded corners or a grid of icons, they would have been laughed out of the court.

Trade dress not about any single design choice but the combination of dozens of design choices which, when combined together, become an aesthetic trademark. And importantly, Apple spent millions of dollars on marketing to promote the fact that the iPhone looks a certain way and operates in a certain way.

The issue is that Samsung cloned this aesthetic in detail for the express purpose of hijacking Apple's existing media goodwill and advertising spend. And it also dilutes the value of Apple's brand.