Simple and universal. Since ever, children learn songs, and, since ever, these present animals : friendly, mean, cunning, not sly...
Children listen, laugh and fall asleep with pictures of savannah, in which they imagine flying lions, giraffes that row on the Nile, armies of lemurs coming to give them a hug. At this age, animals have for only border the children’s imagination.
So, observe the hippo in a beauty salon has really nothing astonishing ; not more than look at the baboons swinging in the air and discover a few characteristics of each animal.