But with the painting elephants, cats, etc..., the people buying into the art tend to know that the art is merely a novelty. And that the relative high price of the art work, is merely going straight to charity (medical bills, food, and shelter maintenance for the upkeep of the elephants or to animal shelters, etc...). Of course, some animal keeper could run this animal as artist racket and pocket the large sums of money (I guarantee not as large an income as the child prodigies are raking in) for their own gluttonous and nefarious purposes.
With child prodigies, the question also entails child exploitation. That the parents are using the hype about the child's alleged art in order to make a lot of money or to sell off art which the artist parent could sell because if the art world knew if came from adults would downgrade the hype on the work and upgrade the criticism to a more suitable, "an adult should have done a 'better job' at painting that" scenario.