When Dana and Spike fight, she channels the Slayer Xin Rong; his answer "Sorry love, I don't speak Chinese" is a repeat of the line he said just before killing her during the flashbacks in Fool for Love (2000)".
Andrew establishes the events of this episode as six months after the battle at the Hellmouth in Chosen (2003). Dana's status as a Slayer is a result of the events from Willow's Slayer activation spell performed then.
Some of the pictures Dana draws are of the Shadowmen from Get It Done (2003). She also marks herself in the same way as Sineya, the First Slayer in Restless (2000).
Dana, channeling Nikki, begs Spike to spare her so she could return to her son, confirming what Spike stated about her in School Hard (1997).
When they are brainstorming in the boardroom, Fred exclaims "Whiskey!" Whiskey was Amy Acker's doll name in Dollhouse (2009), Joss Whedon's series that starred Eliza Dushku.