YouTube children's video has been claimed to have a preponderance of violent, disturbing or otherwise inappropriate content. To assess this claim, we conduct a content analysis of a sample of children's videos published between January 2016 and December 2018. Our analysis reveals an evolving ecosystem involving a variety of production modes and messages which nonetheless bears the heavy imprint of the algorithm-centered commercial incentives of marketing to children and attracting YouTube advertising. Hence, while content formerly causing public concern appears to be effectively policed at this juncture, algorithmic incentives do appear to distort children's content in potentially unhealthy ways.