I concur with AerocatS2A.
When on an ICUS flight I would expect the supervisor to sit there quietly monitoring the other pilots flying. The supervisor is only there for legal reasons (normally to do with min 10hrs on type, etc). There would be no taking over and showing the other pilot how it is done, and no need for 2 crew co-ordination (accept when the aircraft is a 2 crew operation), it is not a lesson. The pilot under ICUS is fully qualified to fly the aircraft and just lacks time on type. The only things I would expect the supervisor to do would be to offer suggestions on how to improve operation of the aircraft, and to assist in an emergency.