How is the poster sure that's etched? The source is just the jpg, trying to find to original post is pretty difficult, assuming I could even read japanese...
Looks more like ink to me. The inking style resembles etching, but I don't think it's etched (unless it's etched and inked).
What's weirdest is that the nintendo logo seems to be external instead of recessed like it is on mine, and the top seems a bit flatter than normal, thoguh I guess that could be due to the lighting, there is at least the line running down the right half where the bevel is.
Actually, you can get this quality of etching done by some street vendors, especially in popular areas like Shibuya. One of my friends had the back of his cell phone etched with an amazing-looking image of a scroll painting; he said the old guy who did it managed it in something like 15 minutes.
After a little research, there needs to be a correction made, the term for carving designs onto surfaces is engraving. Etching involves acid, for example a circuit board has a coating of acid resistant material, which is scratched away to allow the acid to penetrate and score the circuit board.
Either way, the art itself is excellent, whether engraved or just inked.
This looks like drypoint. Where you etch in a picture, then smudge oil-based ink over that, then wipe it away, leaving ink in the crevasses. You can also leave shades of the ink on non-etched areas, depending on how much you take away. I've done it a dozen times to get effects like the image above, but never on a DS.
