
The owner's keys, wallet and cell phones are tagged with radio frequency identification devices (RFID), and when those items are taken from the bag, a small screen on the bag shows which object is missing from its contents.
The LadyBag can also detect and display its owner's emotions on a light-emitting diode (LED) screen on the bag. If the owner hugs the sides, the bag's display screen will show a happy face emoticon. If she fiddles with the zipper, it shows a nervous emoticon.

Source: Project Ladybag | Discovery | Working.com