Atrium 4 - Large gap between mount and speaker / also can't be used as bookshelf speakers?

I am about to pull the trigger on some Atrium 4's for my outdoor deck. They will be mounted vertical like a speaker would normally sit but I'm worried they are going to look funny because the bracket puts such a huge space between the speaker and back of the bracket. I've attached a photo but I am unsure if it will show up as I am new to using this forum.

Also, I am concerned if I want to use the speakers indoors later and bookshelf speakers they wont sit flat due to their round looking shape. Does anyone have any experience with that?