Who a post is for — Public, members-only, paid, or a named set of tiers — where the choice is made, what a locked reader sees, and everywhere the lock is enforced.
Email a post to subscribers — The Email box in the post editor — who it goes to, the five-minute window in which you can stop it, and what lands in the inbox.
The posts list — What Publisher adds to Posts → All Posts — a thumbnail you can change in one click, a badge saying who each post is for, and the featured flag.