South Korea Reinvents the Dining Car, Selling Groceries Right on the Subway

At least one South Korean subway train has been turned into a grocery store, according to photos from a confused tourist. And it's not just a little convenience store or standard food car, either—this thing has refrigerated meat and fish cases, and who knows what else. Is it a stationary grocery-store car, I wonder, or does it travel a route? Could there be a special grocery store line? Ideas like this might be impractical in some respects (try keeping your displays attractive in a regular store, let alone in a conversion job like this), but they open up so many other wonderful possibilities that it's worth the hassle to explore them.