I don't know whether chefs have always put their faces into what they are plating, or whether they are all nearsighted, or whether they saw Jamie Oliver do it and are all latter day copycats.  I don't know that having their noses to the grindstone in this way actually enhances the presentation of meals, or whether they just love to smell their own cooking.  Either way, we must all get used to food that has been breathed on.