The role of an intrusive narrator consisted in comments on and evaluates characters and actions; establishes what counts as facts and values in the narrative (wikipedia). It mainly point out the presence or thought of the author in other words, the author tries to make his presence visible; explaining the whole situation and words to the readers. In most of the novel, when the author is narrating the story, he or she tries neither to be perceived nor to be noticed as less as possible, but Kundera doesn't.
Kundera interrupts the reading with his authoritarian phrase that cause distraction to the readers, such as "it would be senseless for the author to try to convince the reader that his characters once actually lived. They were not born from a mother's womb; they were born of a stimulating phrase or two or from a basic situation. Tomas was born of the rumbling saying "Einmal ist keinmal.?Teresa was born of the rumbling of a stomach?(page 39), this made readers knows where the character came from and what the story is really about; a bunch of though and idea. It may be in somehow a light or a distraction to the readers; it may be a distraction because there are ones that want to find out the unknown by themselves and not suddenly the narrator tells the whole point of it. It may let readers feel uncomfortable about this, because there is no mystery to find out. It may be a light because readers don't have to bother to analyze the story, because the narrator already told and explained them the issue of the story. Personally I consider that Kundera uses this technique is quite unique and it challenge the readers?reading style; it allows readers to read something from