Don't read the spoiler below if you don't want to know how does it work.
WARNING: "So, do you wanna know?" spoilers below
Alright. So, probably there's a [command] which insersts every user's nicname in the [] space. So, I see 'Mr Minio', John sees 'John' and TheBestUsernameEver442 sees 'TheBestUsernameEver442'.