BerryzCelebration wrote:They most likely just shot that part recently.
my guess is this:
HP sometimes does the shooting for the covers on the same day of filming, so with this in mind they probably filmed this at the same time they shot the covers with Kanon. This would make sense since Kanon has the same hairstyle as the covers. It would also make more sense that PV filming occurred on two different days as well since Karin has obviously shorter hair between the dance shot and close-up shot with an obvious haircut.
I'm just gonna ignore this version of the PV tho just because it makes less sense to me than Shuhei's version