When switching to a spear from an empty hand, or from another item, the hand/other item will move downwards as it usually does. However, it gets replaced by the spear model before it fully leaves the screen. In addition, the spear doesn’t rise up from fully offscreen like other items, but from a fixed position that’s still visible on-screen.
Expected would be for the hand/prior item to leave the screen completely before the spear takes its place, and for the spear to rise into view from the bottom of the screen rather than spontaneously appearing and rising up from a very much visible starting point.
This happens with large item models and is likely WAI, as it would require model size detection. Also affects the lowering of held items when rowing a boat.