If I were to excuse myself from our conversation and turn to blow my nose into a handkerchief, odds are you probably won’t think twice about it. However, according to some sources, this would be considered the height of rudeness in Japan.
The reasons behind this difference in acceptance is down to the cultural discourse. Asia has a history of disease that can be spread through saliva and mucus (SARS, Bird flu, etc.) so keeping a handkerchief full of snot in your pocket is a very bad idea. In these countries, they always use disposable tissues. They also tend to wear face masks to prevent the spread of disease.
Within the context of media, discourse refers to any of the factors which effect how a product is created and developed. How a media outlet reports on an event depends on many different factors. If a report on a natural disaster mentions some political issue that the affected country was facing, we have to ask why that was mentioned. Is it relevant to the disaster what was going on in the country’s government, perhaps through some state funding certain precautions could have been taken. Or, is the outlet painting the country as a victim of an oppressive regime in need of outside help.