I can explain that, it’s based on local post compliance laws.
The manufacturer already supplies it in the middle box, which is a valid parcel packaging for their country. However, when it’s being delivered in yours, that one is not allowed so they need to pack it up again in another box, the bottom one, that is an allowed packaging in your country.
This stuff can be absurd at times. And go really wild.
Source: Worked in a wine shop for a few years that sent and received a lot of wine internationally via mail.