Fan Casting Strong Family Resemblance in Sort by Tropes

This is an extremely common practice in animation where, to establish a familial relationship, a child looks more or less identical to one of their parents. This frequently occurs when a show uses garish or outlandish designs, where subtlety and fine physical detail are already lost, and we need a quick visual aid that other characters may not seem to notice. If a family is the stereotypical four-member "nuclear" one, the children will usually resemble the respective same-sex parents.