Depends on the context. Usually, it means you go the extra mile
polish it up and show it off! You want to impress people and put forth considerable effort. It can be slightly negative
inferring that it's all glitter and no gold.
I just watched that for the first time last night! I've never personally used that saying, but I know what it means--just what justamom said. Someone who's putting on a show, usually more style than substance.