When Angel asks Skip about Cordelia's return to Earth after her time as a Higher Being, Skip says, Nobody comes back from Paradise. Okay, a Slayer once..." He is, of course, referring to Buffy Summers.
Julie Benz was called back to reprise her role as Darla, in her first and only scene with Vincent Kartheiser, who plays her character's son. "I loved the dynamic between the two of them," Benz says. "Darla really is the mother who gave up everything for her son and he doesn't appreciate it."
Darla says she was sent by "the Powers" to send Connor a message. While there is no evidence that the vision is telling the truth (and some fans theorised that this could in fact have been The First Evil), Steven S. DeKnight, on the DVD commentary track, confirms that she was sent by the Powers That Be.
To subtly emphasize that Darla finally achieved redemption, the wardrobe department had Darla wear a soft, virginal dress, and lit her in warm candlelight. Julie Benz explains that she attempted to convey "the pure love that exists in a relationship between mother and son. It's an unconditional love, and it's probably the most simple relationship Darla has ever had."
Connor's unwillingness to believe that Angel and the others would betray Cordelia (and to an extent, Connor, himself), and his desire to put their fears at ease indicate that despite the way he acts, he has come to trust and love Angel Inc. as family.