You should never publish posts from your admin account. An alert is displayed, informing the user they're logged in as admin and not to write posts.
If you've changed the default admin username for security reasons, publishing posts from your admin account will reveal your new admin username to unscrupulous folk.
You can read more about this on our blog.
When the admin is logged in, Admin Post Reminder displays an unobtrusive reminder; informing the user they're logged in as the admin.
This lets the admin log out and log back in as an editor or user with lesser permissions before writing or publishing a post.
Normal logged in users will not see the alert.