That was the thing about changelings. They were disturbingly light in comparison to ponies, even accounting for whatever physiological changes Handy's vampire shenanigans had made to him. They looked unusually thin for changelings too, meaning they were likely unwell. Both had the unshorn manes and tails of changelings who had been top side for a while, but hadn't been able to maintain their military cut, and both of them had the same shade of shell cover on their backs, much like Thorax did.