The room that the man enters is an elevator. When he presses the button, the elevator begins to accelerate downward. This acceleration temporarily changes his apparent weight effectively helping him lose 20lbs in seconds.
The man is in a movie theater enjoying a new block buster movie. He takes a drink of his favorite soda and begins to choke on an ice cube. This prevents him from breathing or speaking momentarily. Soon the ice melts and the man is able to breath and speak again.
The bicycles are playing cards of the brand Bicycle. The man and three friends were playing poker and he cheated, that's why there is an extra card. They got so mad; they flung the table, chairs, and cards around and shot the cheater.