In order to understand the importance of foregrounding in the analysis of a text, one must have a grasp of what foregrounding is.
Foregrounding is when an author illuminates (shows its importance) something about a character, setting, or the text itself in order for the reader to identify something about the character (typically done through direct characterization), the setting, or the text itself.
Therefore, the purpose of foregrounding is to simply make something stand out for the reader. This being said, one problem can be seen immediately: some readers do not engage in a text and the information which the author wishes to stand out for the reader does not stand out.In reality, the use of foregrounding is limitless based upon how a reader interprets the author's intent in a text.
Outside of that, foregrounding can be used in order to analyze specific attributes of a character, setting, imagery, or how the text is constructed. A person analyzing a text can look at how the foregrounding of a character is characterized while on a journey, how a setting influences the behaviors of those surrounded by the setting, or how the change in the meter of a line affects a poem.