Not all skiers ski alike. And not all poles should be measured with the same straight legged stance (I mean, I guess if a person skis with straight legs, that works). Depending on skier stance, a person may choose to ride with taller or shorter poles. Skiing with too long of poles can push a skier into the 'back seat', and can create sloppy hand control while skiing aggressively. The more aggressive the skier, the more likely a short pole will help them stay in the 'attack position'.
*Dancing Crane Style reflects traditional ski pole sizing. If in doubt, please choose this size.