Well, based on my current therapy, where a recurring theme is to keep me in the driver's seat, it seems to me he is keeping the control and responsibility with you. It's your journal, your eating issue, and so maybe he just thinks it's appropriate for you to own it, not feel obligated to let him look it over like a teacher would with a child's homework?

I'm thinking he probably thought it would be most useful to hear what bothered you, what you saw, instead of judging it himself? Like in a dream journal, where we focus on the high-impact scenes to us, rather than someone else telling us what matters.