Yes, this is not a new concept for you. This is simply a reminder to continue to build this habit. As you approach an area where you know your student is going to have to slow (for a light, a turn, etc.,) use your eye-check mirror to monitor her eye-movement. Does she check the mirror before, during or after decelerating?

Yes, the difference may only be a few seconds, but those seconds can determine whether or not you get trapped or have an escape route. Seconds matter. This is an important discipline to continue to work on even after your student has his license.