 CONT: Frank and Casper sit talking in a café. Frank asks a waitress  for a cup of coffee, because hed been served coffee in a glass  which makes him a bit dissatisfied. During the conversation between  Frank and Casper, in the first shot the whole glass is full of  coffee. In the next shot only one half of the glass is full. In the  following shot, the whole glass is full again. A few moments later 