GR know video interviews are hard: it’s not something students are used to and that can cause a lot of nerves. That’s ok. Back when I was applying, CC were among the very few firms that asked for a video interview and I had no idea what to expect. I prepared for it like a normal interview, expecting to be asked about my interest in the firm/law and some kind of commercial question. That’s what I got and it was a lot shorter than I had imagined. The main thing I didn’t like was the time pressure: in a normal telephone or in-person interview you have the opportunity to pause mid-question if needed, whereas this was more of a fast-paced, hear the question, make quick notes and answer.
If I was doing them now I’d do lots of practice video interviews first and rehearse (but not script) answers to the typical questions asked at interview. Practice timing yourself. I’d say be careful not to over-complicate things, you have to be concise, go straight to the point and answer without waffle. Unlike a normal interview, partners can’t explore the answer you give, so it needs to be able to stand up on its own as a good interview answer.