What distinguishes the social realism of mexican artist diego rivera's the liberation of the peon from vera mukhina's monument to the proletariat and agriculture in moscow?

The Liberation of the Peon by Diego Rivera and monument to the proletariat and agriculture by Vera Mukhina is very different in terms of social realism. Both works seem to share the same subject - the common man. However, the work of Rivera portrays sympathy to the plight of the subject. Mukhina's work however, is a propaganda tool characteristic of Soviet Art - portraying the common man as the ‘center’ and main driver of communism.