Rings may be a common feature of objects that orbit outside of Neptune.
The images also show that Haumea has an odd, potato-like shape, technically a “triaxial ellipsoid.” To understand that term, think of a sphere: since it has the same radius in any direction, it really only has a single axis. Now squash that sphere down so that it’s still rounded, but flatter. Now, the object has a short center-to-top radius and a long center-to-equator radius. It’s biaxial. Now push in two opposing sides at the equator, forming the potato shape. This splits the equatorial axis in two, one for the long axis at the side, and a second for the short one. Hence, three axes, or triaxial.