Final answer:
The effect of the flashback in 'Pandora's Post' is to provide deeper insights into the characters, particularly Skye's talent and modesty.
Step-by-step explanation:
The question asks which phrase best completes the sentence regarding the effect of the flashback in the story 'Pandora's Post' by B. K. McSwain. A flashback typically provides background information to the reader, helps to develop a character or to reveal a motive, theme, or plot. Without the specific options for the phrases to complete the sentence, it's not possible to give a definitive answer. However, the excerpt already illustrates the effect of a flashback: It offers a deeper understanding of the characters, in this case showing Skye's incredible talent and modesty which set the stage for the current conflict.