Because technology also functions in witnessed presence, in which we share experiences and deliberate upon them, we develop schemata; concerning information and communication technologies, we develop media schemata that help us to operate and understand the machines and their messages and help us to distinguish the one 'agreed' reality from the other. Commercial and political propaganda influence the media schemata people develop, but I would argue that the day-to-day conversations between people also cause the deconstruction of this propaganda. People read through the lines, in a 'samizdat' kind of way, people hesitate to buy the next 'new thing'. The more elaborate the propaganda, and the more it is supported by strong power structures, the harder it is for people to make up their own minds.
We do know that when we speak to someone over the phone this person is not in the same place as we are. Nevertheless the presence of the person on the phone may be much more intense than the real environment where we physically are. Voices are recognized and characterize an individual, so does use of language, and because we share time while we converse, the person on the phone is very present. Before mobile telephony was introduced, it was still possible to know where the phone of the person we were talking to was located physically. As I mentioned before, today we regularly ask each other 'Where are you?' a question that was hardly ever posed before because we always knew where the other person was when we entered into a conversation. The 'Where are you?' question is part of the media schemata of mobile phones; as the understanding of TV presenters is also part of the media schemata of television. When presence is designed with technology, the media schemata define how we will perceive and understand the presence that we perceive. This perception is negotiated in our day-to-day lives.