(Respectfully credit to xepon_sin on Twitter!)

BFF means, Best friends. You're friends with her for years, but you aren't allowed to go to Snezhnaya Palace since the Fatui guards don't let you in. You're staying in your apartment, but she has time to take a visit every night. One night, Columbina knocks on the door and when you open the door she bought a Teddy Bear just for you... Isn't she is so sweet?

"This is for you~"