What strategy is it when the writer uses life experiences/stories to support his argument?

The strategy is anecdote. It's usually used as a hook

Based on the excerpt from the story "Subha” by Rabindranath Tagore, the device that the passage illustrate best is characterization. Characterization is a literary device that refers to a detailed introduction of a character. In this case, the little girl was introduced by describing the place where she went and how it made her feel.