On disc 6 of this set, navigate to the Data Files page (Main Menu to Special Features to The Universe of Babylon 5 to Data Files). Move down to any of the 5 categories on the right side and move right. This highlights the hidden “5.”
Select it and you’ll get the half-minute trailer for the series that aired between the pilot and the start of the series.
Reviews: DVD Talk also has a review of
Babylon 5: The Complete First Season by Holly E. Ordway.