A sketch of Broom doing a quick stretch.

His race, the Syr'l, has an unusual anatomy. Their arms and legs are pure muscle -- no bone structure apart from hands and feet. Because of this, the limbs tend to stretch and squash and bend in various ways that usually wouldn't seem normal. The muscle composition in the limbs is actually pretty tough, and you can imagine the extra spring in their steps is handy for parkour, which is a common way for most Syr'l to get around their world.

It does make Broom look taller here, but he can't keep the limbs that length for very long without straining himself.