I thought it was to disperse the sound somehow. like a speaker box. I'm a producer so I'm always thinking in terms of sound anyway.
I tested it and it sounds a slight bit difference but not enough for the normal ear to hear (not to say I got a bionic ear but I listen different, and that difference in sound could just be the cover itself vs open.)
It could be designed like that because they wanted to have it as a big speaker like they said, then couldn't find a practical way to implement it.
I could just be wrong on all accounts.
