This person is the head of the creative department, be they CCO, ECD, GCD, whatever. Her job (I keep saying her because at WG, she's female) is to make sure all the creative that goes out into the world is up to par. It's not an easy job, I'm sure. Someday I hope I'll know firsthand.
However, crushing your creativity is not all this person does. She also steps in to kick ass when anyone else tries to crush your creativity. This means anyone: clients, account folks, even fellow creatives. Because her job it to protect good ideas, and make sure they have a place to grow.
So appreciate your ECD, even when he or she smiles thinly and silently shakes her head no.