Getting a different result set than the lecture's

Hi

I ran the second query suggested in the lecture (the one with IN), and I got 8 rows, the two main results have repeated. Could anyone help me see what is wrong here?

SELECT
    e1.*
FROM
    emp_manager e1
        JOIN
    emp_manager e2 ON e1.emp_no = e2.manager_no
WHERE
    e2.emp_no IN (SELECT
            manager_no
        FROM
            emp_manager);