Are Shetland ponies show ponies?

That will depend upon the type of Shetland you are looking at.... British or American.... And what you are looking at doing with them.
American Shetlands have been bred to be great all around ponies, from the somewhat drafty Foundations to the highly animated Hackney crosses there is something for everyone... I show my Foundation American Shetland in open shows both in hand and driving and do pretty well, then turn around and go on a trail drive. As for temperament... buy registered. Bad tempered ponies are not tolerated in the show ring.