In reply to Al Evans:
Its not humane and can be stressful for the fish as it has nowhere to hide from potential threats, which in a bowl can come from all angles. Also the shape of a bowl doesn't allow much gaseous transfer at the surface reducing oxygen levels in the water, exacerbated by hot studio lighting (unless a bubbler is used). As well as that, goldfish get large and like lots of space to swim, the 'grow to fit the tank size', is a myth and they are actually stunted with health effects.
But under tv production rules, the fish will be provided by a specialist animal wrangler who will likely remain during the filming to ensure the animal's welfare. The fish probably has its own trailer and will explode into a rage any time a runner brings it a can of diet coke, opened, but with the opening tab not bent back out of the way
Still, it's not great to perpetuate the idea of keeping goldfish in small bowls and with no decor.