The handle attachment is in the form of a frontal siren.
The function of a handle attachment is to secure the base of the handle securely to the body of the vase; a broad surface provides a stronger bond. From a purely mechanical viewpoint, the siren with its extended wings fulfills the purpose effectively. She wears a silver fillet.
Dillon, Douglas and Thomas Hoving. 1970. "One-Hundredth Annual Report of the Trustees of the Metropolitan Museum of Art for the Fiscal Year 1969-1970 Report of the President and the Director." The Metropolitan Museum of Art Bulletin, 29(2): pp. 82-3.