I found these interesting looking milk bottles. It says "Farmer's Milk - fresh directly from the farm." Yummy!! Anyway, the bottle also says it is an "Eco Pet" presumably meaning an eco-friendly pet bottle. The small picture on the bottle seems to indicate that you can squash the bottle and make it into a small garbage.
I thought the bottle looked pretty interesting, but I am not sure about the eco-friendly part. Why not just use the paper container instead? Maybe there is a reason, which I have not yet explored. If you have any information on that, please let me know.
Eco friendly pet bottle is also big in Japan. Here is the CM from Coca Cola Japan: