When the image contains a parent and a child and the child is smaller.

If the parent is not in the image, do not tag as smaller_child. Everybody is somebody's child, with rare exceptions of characters that have no parents such as deities and gems.

If the character appears young, tag as smaller_young. A child may not be young if they have grown up to be adults, and a young character should not be tagged as a child if the parent is not in the image.