Executive chairs are super comfortable and make you feel regal. However, on video they make you look small. The backside of the chair goes up to your ears and kills the needed seperation between you and the background. Plus, your talent is going to end up swiveling and that's going to make your talent look impatient as well.
Use a bar stool or use a chair with a short back. Sit back alll the way and keep your back straight.
That feels better, doesn't it?