What level are you teaching? If a student is a beginner, then that student has to learn everything, including how to sit at the piano, and how to move. You mentioned both having the score. In that case, the student must be able to read.
I'm working with my teacher via Skype. I'm an adult and I already know how to work. The most difficult part has to do with technique, and unfortunately since I was self-taught years ago and then resumed decades later, that is an important issue. Interpretation, timing (rubato etc.) are relatively easy to bring across.
In regards to technique, I've seen tutorials in Youtube. The teacher can have a sophisticated camera to show his hands, his arms, the angle of his body, feet etc. But observing the student is another matter. Do you work with any of that?