las cosas que no entiendo: sachetes de leche / the things I don´t understand: bags of milk

So I understand I am in a culturally different place but one thing I still haven´t quite wrapped my mind around yet are the bags of milk. Yes, in Buenos Aires I buy my milk in a bag.:

I even had to buy a "lechera", a milk holder:

I cut a small corner off the top of my milk bag, put my milk bag in the lechera, and then pour my milk:

Here in Buenos Aires you can get almost anything in bag. For example, bags of spices:

and bags of yogurt:

Just another fun difference I thought I would share. Happy Tuesday!