She obviously isn't clued in to the second feed part. For anyone else that may read this, hold back some treat food, a decent amount, and intercept the returning hen with it. If you're lucky (?) the hen will expect this after a couple of days and may even come and bug you for it before she goes back to her nest.You may be right. As I am remembering it Phyllis would eat and drink once she broke out of her trance. Then she would poo. Then she would dustbathe. After that grooming with the tribe. Then she would head back to the nest. She did not eat before going back onto the nest.
Here is video.