Hello, I am a Lego Investor / Collector in Korea. Lego Korea (the official arm of Lego sales in Korea) is in an unfortunate position where Lego boxes have been flagged as "violators" of a new Korean government campaign to reduce wasteful packaging. This includes fancy cosmetics which are in a jar, in a box, placed in another padded box, and then shrink wrapped, with another band like box on top of it. But for Legos, they have been flagged for having boxes larger than needed for the content inside. So the government has put a soft "penalty" of sorts on Lego boxes, requiring that they be opened, and a free little promotional item is placed inside to fill that space (like a crappy piece of tupperware), with some literature about how the Korean govt through the KC (like the UL safety/quality mark, but Korean) is trying to encourage consumers to protect the environment, and reduce trash waste by getting the consumers accustomed to more efficient packaging.
I don't know at what step it happens in the distribution process, but either Lego Korea or the KC (Korea Certification org)
1) open the original Lego box, breaking the seals
2) stick in this crappy piece of tupperware in the extra space
with some information about more enviro friendly & efficient packaging.
3) RESEAL the box with the exact seals that Lego uses.
Since it's done by the Korean govt (KC), Lego must have provided these seals, or are cooperating in some way.
Not ALL Korean legos have this, as these government pushes for sleeker packaging are not always in force. But they have been lately.
Experienced Lego Collectors in Korea call it "I-joong-seal" or in Korean letters ???. Literally translates to: "Double Seal"
Experienced collectors all know about this, and consider it an annoying but non-product-devaluing government regulation.
After all, you can use the little tupperware knick-knack to help sort during a build.
HOWEVER, it does freak out newer AFOLs here, and understandably any sort of buyers who receive this product abroad.
In the situation that TabbyBoy describes. My guess is that if he shipped a large volume of NISB sets to Korean buyers, those boxes might have gotten flagged by customs, and received the tupperware insert, and double seal (re-seal) treatment by the KC, before arriving at the doorstep of their newbie AFOL.
The only advice I can give when confronted with a Korean "double-seal" is to make sure it looks like two official Lego seals slapped one on top the other (usually pretty neatly, btw). And the top one should be sealed. And expect a "surprise in the box" when you or someone else opens it.
It's not always tupperware.
But it's always something cheap and throwaway-ish.
The irony. By trying to get consumers accustomed to the idea of slimmer, less wasteful packaging, they give you something you'll likely just toss away.
I hope that clears up some of the confusion that buyers / sellers may have been experiencing with transactions that go to/from South Korea.
The largest Legoland in the world is set to open in 2 years in South Korea, so I imagine the frequency of these secondary market transactions with Koreans will only increase. Which I think is a great thing! But, I'm hoping that some misunderstandings or suspicions might be avoided.