As you can hear in the video, Geoff was somewhat less than thrilled that this chives were being nibbled. Scarlett's startled look at the end of the video is due to Geoff coming at her with the Spray Bottle O'Discipline, which was enough to get her to back away from the chives.
Temporarily. They're delicious, after all.
ETA: Thank you to Anju, who pointed out that chives are toxic to cats. Fortunately, Scarlett was fine after this video was taken as she didn't actually ingest much. I'll make sure to keep her away from the chives in the future, though!