From the D23 website…
Our friends at Disney Theatrical Productions invite D23 Members to attend a special performance of Mary Poppins at the Ahmanson Theatre in Los Angeles. Members will receive a 20% discount on select seats in various seating locations throughout the theatre as well as a voucher good for 20% off all merchandise at the show.Members will also get an exclusive post-show experience with the Mary Poppins cast and a top-secret surprise guest! While we can’t say who the mystery guest is, we can tell you that he appeared in the original film!