The Unanswered Phone

In the first episode of the comedy The IT Crowd, we watch a character sitting in a room when a phone starts ringing. The character sits there, reading the paper and ignoring the phone, while we become more and more uncomfortable. 

Why is it unpleasant? I think because an expectation of contrast is frustrated. See next post.

There are a couple of side issues.
 - One is our reaction to a room that is empty except for the phone. If it rings it may cause more or less discomfort. I am told there is a Tom Stoppard play where characters appear from the side lines to answer the phone. This, in turn, leads to several jokes (mostly from Bob Berger) using permutations of an empty stage and actors, all of whom could have additional cell phones in there pockets. My joke is that when the character finally answers the phone, suppose it goes on ringing?