A circle of speaker holes pepper the bottom edge, and it naturally rests at a 70 - ish degree angle that makes it easy to see from anywhere in a room. (techhive.com)
An obvious speaker hole is missing; instead there's just a tiny pin hole on the back. (the-ebook-reader.com)
My initial feeling is that it indicates a transition from the old speaker holes to the new edge - mounted ones. (9to5google.com)