In patch 5.4 Blizzard has added a new icon type to the minimap called "vignettes". These are really similar to the old quest-monster icons, with the super-important distinction that there's API support for telling us where they are and what they're called. Mostly they're on the Timeless Isle, where they point out rare mobs and chests.
Cool as that is, they're off in the minimap on the corner of your screen, and you might not even notice them. So let's shout about it a bit when they show up.