Big house, shiny new car, a custom-made suit, an expensive watch, cool sunglasses... If you have these things, you have the trappings of success, which means you own things that give you the outward appearance of success.
The word trappings originally described the decorations people attached to their horse's bridle and saddle. The goal was to make a statement about the rider's power and privilege. Today, we still have trappings, but they take other forms, such as expensive clothing with big logos or big diamond earrings. Trappings are material items that tell the world that someone has money — or a credit card — but not about who he or she is on the inside.