litter on a stick
n.— «Pictures on billboards can be beautiful, ugly or just ordinary. But when they are enlarged to 700 square feet, raised 100 feet in the air and randomly spread along every street, they become a form of litter—litter on a stick.» —“That ‘Upscale Art’ Quality Claimed for L.A.‘s Billboards Is Actually Litter on a Stick” by Edward T. McMahon Los Angeles Times Aug. 22, 1989. (source: Double-Tongued Dictionary)