It's not a rectangle, it's clearly either an iPad or Galaxy Tab. It's a rectangular slab of particular dimensions/proportions, rounded corners of a particular curvature, and a 4-sided front bezel of a particular, uniform width. In combination it's immediately recognizable as an iPad or iPad mimic.

If it were a rounded rectangle being patented, then the patent would look like this [0], not like that [1]. [0] is not recognizably an iPad.

[0] http://mathworld.wolfram.com/images/eps-gif/RoundedRectangle...

[1] http://cdn.arstechnica.net/wp-content/uploads/2012/11/D60728...

full disclosure: I'm not "pro-Apple" in this case, I own a Galaxy Tab 10.1, and think design patents are a silly thing to enforce.