The paper aims at highlighting how our primary understanding of others' actions is rooted in the mirror mechanism. To this end, the anatomical architecture of the mirror neuron system for action will be outlined as well as its role in grasping goals and intentions in others' motor behaviour. One further step through the looking glass of social cognition will be referring to the ubiquitous emotional colouring of actions and considering its links with the motor domain. This will allow a clearer perspective on the mechanism underlying our abilities for emotional understanding and on cases in which these abilities are amiss, as in autistic spectrum disorders.