Even if the Ds don't look like mirrors to you, they still are mirrored representing mirrors. Without the Ds there would be nothing mirrored taking away the "mirrors" in "smoke and mirrors". I think the mirrored Ds standing for "Dan and Dave" goes perfectly with the theme of this deck.
I'm just curious what were you expecting a deck produced by Dan and Dave called Smoke and Mirrors would look like?
I think this deck is awesome. The Ds being mirrored are awesome. The Ds can be explained having a resemblance to actual mirrors, that is intelligent.
My real name starts with a D, so this deck is personalized for me.