Minecraft wiki entry for Item_(entity), associated text: Items have two possible appearances, generally corresponding to whether the item appears as a 3D or 2D shape in a player's inventory screens. 3D items appear as their 3D shape, miniaturized to about 1⁄4 scale, while 2D items appear as 1⁄2 scale with all the pixels extruded into a cube. Both types slowly rotate and bob up and down.