Hiya, (I'm Jack Clark) - this is a good point. The child probably gets about 50 to several hundred distinct 'frames' of the chicken. Still, a remarkably small number of examples.
It would also be a terrible drawing. An adult who had seen many other types of birds would be able to do much better, as they would have learned more abstractions - for example the experience required to condense a complex visual pattern to, say, "mottled".