Rounded corners question
When I create a square with rounded corners and I go to Properties I see these buttons at the bottom:

Whether I click and drag the one on the left

or the one on the right

I get the exact same results and it just changes the rounded corners of all 4 corners. Is there a different situation where those behave different?
Also, what are those rectangles in between the buttons? If I click them their border turns blue, but that doesn't seem to do anything. Also, I can't double click and type anything, which seemed to be intuitive when seeing those boxes.

