This nice little video is from a blog post by CK Training/Callie called “Are you “Ahead of” or “Behind” the Motion when you ride horses?”. It offers a good visual example of what this looks like, and what causes it. I think it will be helpful for newer instructors.
Note: This is not professional advice, this is a blog. I am not liable for what you do with or how you use this information. The activities explained in this blog may not be fit for every rider, riding instructor, or riding center depending on their current condition and resources. Use your best personal judgement!