At this point in the connection process, two security checkpoints have been crossed. On the one hand, the explicit setup and delivery of the request acts as a security filter to limit the session time and permissions on the requesting computer. On the other hand, the password option adds further security.
The next security checkpoint is the required active approval of the Remote Assistance connection by the Novice. Finally, the most critical security checkpoint is that needed to gain full control of the Novice's computer. This checkpoint is similar to the third in that it also requires an active acceptance of a request from the helper before control of the computer is passed to the helper.