Ot at least I think it's just a skin--as opposed to a 3DS XL (or 3DS LL, if that's how you roll) system that's literally been covered in THE "DENPA" MEN graffiti.
Regardless, it's a beauty, isn't it?
As far as I can tell, it was created by someone who goes by the handle "detteiu9" on Twitter.
He or she also has a pixiv account and is known as Teu (てう) on that site.
A handful of completely adorable "DENPA" MEN-inspired pieces of fan art can be found on Teu's pixiv page, by the way, so I'd highly recommend checking it out if you're even half as interested in this series as I am.
(Via photozou.jp by way of gonintendo.com)