“The site-specific Wall Drawing #679 – a grid of blue squares segmented by red and yellow lines – had been commissioned by the late William F. Stern, a local architect and the home’s previous owner. It was executed on the roughly 30-by-10-foot wall in the early 1990s, and covered up years later when the house was sold.” Now the owner is uncovering it – problem is, she doesn’t legally own it. Artsy‘s Isaac Kaplan explains.