I can’t help but think about these shots of Buffy, at the end of each opening. And how they help support the theory that when Buffy came back from the dead at the start of season 6, she came back wrong.
It goes a long way towards explaining why she’s so uncaring, domineering and callous in season 6 and 7. Some small part of her soul or essence was left behind in heaven, because Willow’s resurrection spell was interrupted by the biker demons at 99% completion. Buffy worries about this during Season 6 (when Spike’s chip no longer recognizes her as human); Tara gives her some bizarre, vague Superfriends-esque explanation about “molecules”, and then it’s never brought up again. Tara was lying.
Now these shots at the very end of the opening credits? The show changed it for some seasons (top row: season 1-2, season 3-5) (bottom row: season 6, season 7), but it’s always of Buffy standing alone, looking powerful and defiant. Except… in the last two seasons (season 6 and 7), it’s not actually Buffy at all. For Season 6, they use a shot of the Buffybot from the battle with Glory; in Season 7, it’s a shot of The First pretending to be Buffy from the season premiere.
I’m willing to bet this was probably intentional. The Buffy of Season 6 and 7, isn’t really the same Buffy we knew, from season 1-5.