If you train your slave properly, you can expect to see this kind of pride on it's face after an intense session of abuse because it's position in life is so thoroughly reinforced that it finds it's purpose in serving and accepting daily punishment.
It hadn't cleaned the floor before I got home from work. So I tied its hands behind its back, placed it in a stress position and then restrained it in place. It will learn or it will be sent back for re education.