Daphne gets upset that she was "played by an extra" in this episode, and says, "What, Sarah Michelle Gellar wasn't available?" Sarah Michelle Gellar plays Daphne in the big screen live-action Scooby-Doo movies.
The "extras" that portray the "alternate" gang are in fact animated caricatures of the voice actors and are properly matched to their characters: Casey Kasem (Shaggy), Frank Welker (Fred), Grey Griffin (Daphne) and Mindy Cohn (Velma).
When the gang is getting their mugshots taken, the number "69" appears in each of their individual placards referencing "1969", when the original series premiered on the CBS television network.
The opening and closing credits for this episode are different.
-SPOILER*
At the end of the episode when the bad guys are unmasked, the characters who played the fake Velma and Daphne seem to be modeled after the real voice actors Mindy Cohn (Velma) and Grey Griffin (Daphne).