The original question had to be edited, and I tried to combine both in this question. There is a social disdain about those who are not physically attractive in the social context of Blais' work. The opening sequence where Patrice is being admired for his beauty while Isabelle-Marie is being neglected because of her lack of physical beauty helps to establish this context. The custom of revering beauty is something that causes some individuals to be loved and those who lack it to be marginalized.
Louise represents this social custom herself as it embodies how she carries out her maternal duties and responsibilities. Louise is incapable of loving anything that fails to represent beauty. She marginalizes Isabelle-Marie for this and when Patrice loses his beauty, he is silenced by being institutionalized. There seems to be a social custom in which beauty is revered and valued over all else. This social context helps to establish why emotional connections are challenging to forge and how the social context of beauty ends up becoming the source of much in way of resentment, suffering, and miscommunication between children and parents.