I like what you were told OP.
The best bit of advice I had as an older, unequal and not very competent beginner is a matter of controversy, but has been my secret safety net.
When going round a circle or corner, picture the centre of the circle and keep your shoulders and hips aligned with the line (radius) to that centre point. If a teacher is lunging you, he or she should see you sideways on and not be able to see your outside shoulder at all.
This advice has classical credentials - but it kept me secure in the saddle at novicey moments I might have fallen, canter round bends out hacking or trotting bareback or being run away with in the school. So easy to forget these magical bits of advice and good to be reminded. Thank you.