Your analysis is interesting and we could add some comments on the figurative art advocated by socialist realism: Art must be socialist in its content, national in its form and aim at efficiency by serving the struggles of working class.
It means first of all knowing the life of the working class in order to be able to represent it truthfully. Here it is not the sadness of the adults which is represented but its seriousness, we do not praise the comfort of modern dwellings but their efficiency. Life should not be represented as "objective reality", but as reality in its revolutionary development. The socialist realism must contribute to the ideological and educational transformation of workers in the spirit of socialism