The episode's title, "Believe the Unseen," is the motto of the 1st Touch Foundation, started by baseball player Derrek Lee. Lee, a guest on an earlier episode of "ER," has a daughter with LCA (Leber's congenital amaurosis), the disease featured in one of the storylines.
The scene with Kayla singing "Beautiful" was what got Avion Baker the role of the singing voice of Uniqua on The Backyardigans during it's fourth and final season.