Populism by the media manifests itself when media organizations explicitly engage in their own kind of populism. For example, when they act as advocates on behalf of the people, with a critical attitude toward power holders; or when they actively express hostile opinions toward social groups. Some media outlets can be openly sympathetic to populist actors and adopt many elements of the populist rhetoric in their work.     

Source:
de Vreese, C. H., Esser, F., Aalberg, T., Reinemann, C., & Stanyer, J. (2018). Populism as an Expression of Political Communication Content and Style: A New Perspective. The International Journal of Press/Politics, 23(4), 423–438. pp. 429