Yes, 19 chapters in, they are still more amazed at simply frying fish, than they are about using a freaking PLASTIC bottle to pour sauce on it.
Let's not even mention the gaz stove, or the faucet of infinite water...
@Robbini the bottle might be glass, but it's cork is clearly in plastic. They look exactly like the ones you can find in supermarkets all over our world. :)
The three North Kingdoms are most likely that world's versions of Norway/Denmark, Sweden, and Finland.
Edit: Also the little girl from the earlier chapter is most likely the little sister of the current Emperor, who was married off for a political alliance.