Are you weird? Or just Japanese? Do you have a thing for panties? Do you like dressing up things? Do you like bottles? (??) If you answered “yes” to most of these then we have a good news for you: Bottle Panties. You can now buy several kinds of small panties that you then put on the bottle. Any bottle but we are guessing yours might be milk bottle. This is to make the bottle more decent and not expose their “nakedness”.
OK, joke aside – it is said that this is to catch the beads of moisture which appear on the bottle surface if the drink is cold, preventing them ruining your table. However, we are not sure. People are weird.