As far as decorating with wall mirrors and polka dot wall decals go, I think the mirrors are great but I think that polka dots on the walls are better for tween and teen girls' bedrooms because some of the mirror wall decorations are too "grown-up" looking.
But, YEAH, I love them both. I just think that the mirrors would look better in a master bedroom and that either painted polka dots in wild colors or polka dot wall stickers look so cool in bedrooms for teens.
Or maybe you could mix the wall mirrors and polka dot wall decals all over the walls and ceilings. Now THAT'S a cool bedroom decorating idea if I've ever heard one. You could alternate the two kinds of decorations in a random fashion and add some bright colored lights maybe to match the fabric of the comforter set. The reflections of the strobe lights in the mirrors would be amazing.