CST embodies an evolving tradition of political theology with certain enduring characteristics: the dignity of the person, the common good, reciprocity of governments and citizens, democratic rule and just laws, advocacy for the marginalized, and alliances among Christians and others to improve social life. While official CST still refers primarily to papal and episcopal documents, the present Argentinean pope, Francis, travels extensively to encounter the realities of church and politics in multiple cultural contexts. He goes beyond statements, addresses, and encyclicals to include symbolic actions, liturgies, and informal interviews as media of expression. These seem to invite further interaction to define and refine the church's political presence". 

With reference to these opening sentences from Cahill's conclusion, what is the relationship between "official" and "unofficial" media of expression in how Pope Francis communicates Catholic social teaching?

What do, for example, informal interviews achieve that papal documents do not, and vice versa.