There is a central locking point in the stem, it locks the handlebars and it locks off the flow in the hydraulic brake lines, so the wheels can be locked. Brakelines are inside the frame, stem, handlebars. Thieves need to cut into these vital parts to mess with it.
The handlebars lock may not always be practical; it was mainly designed to fold together for easy storage. Locking the bike with the handlebars was just a bonus. In the concept a cable lock was integrated inside the long arch which could be pulled out, wrapped around a fixed object and inserted in the stem, double acting as a steertube lock.

Central locking point

Locking the handlebars

The handlebars as a U-lock