This is a great chance to show that you understand who you are. Graciously share your best asset, and explain how this asset affects your library. One possible example may be sharing that your best asset is your ability to create a connection with all types of people which has helped you work with patrons from all walks of life. Struggling to come up with your best asset? Think about the common praises you received in past performance reviews, or ask a respected colleague for their opinion. With this option, tell the interviewer that people have told you this is your best asset, and explain how you feel it has positively affected your library.