The mirror image of Ds have a double meaning. The Ds are actually 2 mirrors standing and facing each other. They appear to be like the old fashioned mirrors magicians used on stage. I hope this makes more sense to people now why it's designed the way it's designed. The swirls represent smoke and the Ds represent 2 mirrors facing each other. It also happens to look like 2 Ds, standing for Dan and Dave. Obviously everyone noticed the Ds, but not the mirrors. I thought due to the name smoke and mirrors, that it would have been more obvious to people that the Ds are also mirrors. This was a very clever design, don't you think?