A condescending phrase used to preface the dissemination of an important (often revolutionary) piece of information from a self-identified superior being to a subjectively-determined inferior being. Usually used during paste up, sometimes as an insult, though most often as part of the Denebola vernacular.
Let me help you out: this thing isn't a work of art.
A Shackteau is a humble, weather-beaten, structurally questionable shelter located in a spectacular or highly coveted place—Wales, Jackson Hole, Sun Valley, Crested Butte, coastal Maine, the Alps—where the building itself may be worth almost nothing, but the dirt, view, access, and mythology make it absurdly valuable.
In use:
Shackteâu - We thought it was an abandoned shed until the realtor called it a rare alpine Shackteâu with unobstructed views and listed it for $2 million.