There's overlap, of course. I mean to cast no aspersions on our graphic design site--I wasn't even aware of its existence and I'm sure its users are wise and experienced--but in general I would actively avoid advice from graphic designers concerning the design of statistical graphics unless they had statistical credentials as well. And even then I would be cautious.
(My favorite example of how far wrong you can go is Bounford's Digital Diagrams book. Written by a well-established graphic designer and promoting itself as "effective design and presentation of statistical information," this book consistently provides hundreds of examples of everything Cleveland, Tufte, Wainer, et al. have shown to be truly awful approaches: an atlas of chartjunk and other distracting embellishments of all kinds guaranteed to obscure and warp any information that might have been present in the data.)
Thus, when questions come along even about seemingly trivial elements of the design of statistical (or scientific) visualizations, I believe they are very much on topic here.