What is Seppings' reason for interrupting Stilton and Bertie's scuffle in Chapter 17?

As Stilton is chasing Bertie around a couch in Chapter 17, the house butler, Seppings, interrupts them. Stilton demands to know what Seppings wants, and Seppings informs them that someone has arrived at the door, at which point Daphne Dolores Morehead makes her first appearance.