Seoyeon explains that staff members sometimes create fake fan accounts and blend into the fandom by following lots of real fans and gaining mutuals. By doing this, they can monitor conversations on Twitter more closely.
Even if fans try to avoid detection by censoring or altering the idol’s or group’s name, those posts can still appear on the staff-run account’s timeline through their network. Essentially, it’s a way for companies to keep track of fan discussions and shared content without being obvious about it.