The article discusses Facebook's feature that allows users to see which companies have associated their off-Facebook activity with their Facebook account. The author discovers a mysterious company called 'Lan Tim 2' that has shared their activity with Facebook, despite not having made any purchases from them. The author investigates and finds that Lan Tim 2 is a white-label operation that supplies custom printed apparel, and that their activity was likely shared by another company called Spreadshirt. The article highlights Facebook's lack of transparency in providing meaningful data about the companies that share user activity.