Brentwood is a verdant, upscale neighborhood on the westside of Los Angeles. It’s filled with mansions and luxury condos and shopping to match. Its style can be summed up in three words: Understated, fashionable, and expensive. There is little — if any — street art in the usual sense of the term, or public art for that matter. But the burb is home to one of L.A.’s most visually striking and singular murals, a massive painting of a giant tree on the side of a condo building on a slopey, fashionable stretch of Barrington Avenue. The mural shows a tree in reverse silhouette, a white stylized shape of a tree from roots to empty, wiry branches on a dark gray background. It’s simple and elegant and unmissable as you drive past it. The irony is in an area that is among the leafiest and greenest in Los Angeles — Brentwood is filled with trees —  there is a mural of a tree without leaves.