What username is being displayed here, Farcaster or Comm?

If it's a Farcaster username, why do we need to do this? I thought you indicated the usernames were at most 16 characters?

In the linear comment below I specify that there's the possibility of people creating their own Comm frame url with an unusually long username as a parameter.

Unlikely but I included this just in case to prevent anyone from being able to render a frame with a username that goes out of the Thread Invitation box