I think the 'rounded corners' description refers to the top plate of the plinth. The actual corners of the plinth are still squared.
The fact that a 'cosmetic' change with rounded corners on the top plate of a plinth can generate even a whisper of inquiries attests to Ive's 'BSness '. It is of the highest order, though I do like my iphone 8 with rounded corners. He was brilliant once.