With design patents, you don't have to specify transitions or curve radii. It's enough to draw that the corners are curved. There is no examination of the content of design patents and lack of specificity is generally not considered a problem by the PTO and courts.
Samsung has been copying Apple to the millimeter, they have discovered a book with ways they should copy Apple, and they were spreading misinformation to the consumer like "Samsung makes the iPhone for Apple", or "it's like the iPhone, but bigger and better", and other BS.
Also, there is no problem in making a rectangular phone, but making the edges EXACTLY the same radius as Apple's? That ridiculous.
Samsung more than deserved what they got, from their advertising, where they attacked Apple users and offended them. For that reason, I will never buy a Samsung device, even if it's 100x better and 1/100 of the price of an Apple's (or everyone else) equivalent.
And their unilateral comparisons to Apple on their product announcements? Ahah, ridiculous!
I seem to remember in the Apple v. Samsung case there were several of these on concepts like "a rectangular phone form factor" or similar...