Answer: This quote illustrates the fact that we often use stereotypes to draw conclusions about people.
Step-by-step explanation: Gilbert is highlighting the fact that we often use stereotypes to fill in the blanks about people, sometimes correctly (a woman is threading a needle) and sometimes incorrectly (the woman is threading a needle to suture an incision made during surgery). Ultimately, stereotypes are assumptions we make to make the world seem more predictable, but those assumptions can often lead us astray.