Originally the phrase "cameo role" referred to a famous person who was playing no character, but him or herself. Antique cameo is usually a low relief carving basically of a cameo role. You can see the connection and the ispiration that drove cameo portraiture.
Cameo Portraiture was popular in Victoria England. The straight roman nose does not indicate the cameo is "older" it simply means the cameo role was earlier. A cameo artist can carve an ancient cameo role today.
