"i had no intention of shooting the elephant—i had merely sent for the rifle to defend myself if necessary—and it is always unnerving to have a crowd following you."

what purpose does the phrase separated by the em dashes serve in this sentence?

the phrase is meant to draw the reader away from the sentence.
the phrase is meant to qualify the author's actions in relation to his first statement.
the phrase is meant to restate the same concept as the first phrase.
the phrase is meant to support the final phrase of the sentence.