Metaphor is the figure of language that transports the word (or expression) from its literal meaning to the figurative sense. It is a comparison that is expressed without the terms that characterize a comparison. In metaphor, a word is used with the intention that an implicit meaning stands out in it and leads to the interpretation of what is being said.
In the phrase "His son was too buried in the magazine he was reading" the metaphor was used to compare "being stuck in reading" with "is buried in reading". It means that the boy was very absorbed with what he was reading in the magazine, as if trapped, buried.
