The Clamp postcard comes from Shanghai, China, in a Postcrossing Forum anime & manga trade.
The colorful card of sea lions balancing ice cream cones is part of a swap-bot “chunk-o-cardboard” trade, and it comes from the same member in Geel, Belgium who previously sent me the hippo card I also love. I believe this is not really an ice cream snack, but actually a room-temperature biscuit, but perhaps the sender will come by to correct me if I am wrong.
Lastly, from Taichung, Taiwan, come the deliciously-illustrated Taiwanese foods, mine thanks to a USA-Asia tag trade on Postcrossing Forum. The sender tells me:
“(Taiwan is) famous for its traditional snacks. It’s cool you’ve tried before. Maybe next time you could try the ones on this postcard.”
Stamps! That rose one is printed directly on the manga postcard.