Agree with the general comments here on leadership. IMHO in any organisation it is the leaders that set the tone. I think that what can happen is that at the start of the flight (so when the crew all collect together and before they walk onto the aircraft) the IFL will have an opportunity to talk to them and set the tone. If the IFL sets clear expectations on who will be doing what role and to what (high) standards, then I think that sets the tone and the experience for passengers. But if the wrong tone is set then the crew (being human beings) may respond by putting in little effort, because they have received the ‘wrong’ message at the start. Just my two pence.