For items that scale directly to your level, they do scale at ilvl = rlvl. If you go to the wowhead page for https://www.wowhead.com/item=3053/humberts-chestpiece&bonus=3642&ilvl=19&lvl=19 (let me see if i can get the tooltip correct...) and adjust the slider, you'll see that at level 19, it...