In some parts of Canada, milk is bought in bags. 3 bags are packaged in 1 bag totalling 4L(~1gallon). A plastic jug holds the bag while the corner is cut to pour
Holy Cow! Milk in Bags | Bon Appétit
MELAMINE MILK BAG PITCHER 7.25" – One of a kaind
Here's why milk comes in bags in parts of Canada | CBC Radio
Amazon.com: Baby Juice Box Holder Juice Bag Holder for Toddlers No Squeeze Adjustable Folding Food Pouch and Milk Box Holder for Kids No Spill 2-Pack (Green&Pink) : Everything Else
Vintage Milk Bag Pitcher Red Milk Bag Jug IPL Plastic Made - Etsy Sweden
IPL Hard Plastic Milk Bag Pitcher Breakfast Juice Bag - Etsy
So apparently I need to explain to the in-laws how bagged milk works : r/funny