Again it happened. My daughter needed a new pair of poles and the ski shop sized her using the upside down pole thing and they are always too short. Luckily, my other daughter has properly sized poles and is the same height and we had hers with us. After he sized her wrong, I insisted on the same size as my other kid, and of course he looked at us cross-eyed as he handed us the poles.
I'm no equipment expert but I know a short pole is a terrible tool to use and worse yet, to use to learn to ski properly. Short poles cause one to bend too far forward to plant and promote a slide instead of a carve.
I've taken a number of my friends kids skiing and have usually noticed that poles, even ones recently purchased, are too short using the typical ski shop fit. I've seen the same thing with friends and have noticed the improper skiing they promote. They always do better with properly sized poles. Somehow, the ski shop doesn't understand the height that is added when one is on a ski and a ski boot compared to wearing street shoes.