How does David Lynch use film techniques to portray ordinary life as nightmarish?

The viewers of "The Grandmother", a short film directed by David Lynch in 2009, have had different opinions on the film. Some viewers consider it as a great cinematographic piece that could be one of the best ever created, while others see it as complete nonsense with no meaning behind it whatsoever. In this film, Lynch tells the story of a couple who have a child after getting married, a son who they don't really want who ends up growing up in an abusive environment. One day he finds himself in a dark, sinister room, where he plants a seed that grows up to be his grandmother. 

David Lynch's short film could belong to the surreal cinema that presents an aesthetically intriguing world while speaking (not literally) about different morbid topics. He uses no dialogue in this mix of live action with animation to show the child's point of view, who sees life from an exaggerated perspective. Instead of using dialogue from the actors, Lynch makes them communicate through unrecognisable noises that sound mostly sinister to the audience. Those sounds represent the animalistic sides of the human psyche while showing abusive and inhuman interactions. 

Lynch uses dark and unsettling soundscape while treating morbid topics, such as abuse, to portray an ordinary life as nightmarish. He also compares humans to animals through their form of communication to dehumanise them and present them as savages. Lynch may have decided to follow this comparison as a way to express his own opinion about abuse, child abuse in this case, while being creative and coming up with a morbid world to support his opinion.