Magical net is an allegory for *upaya* - a skillful approach to teaching Dharma by taking advantage of student's own inertia, as opposed to pushing student by force.

In other words, when a good teacher of dharma masters the skill of seeing from the student's (often somewhat confused) perspective, a talented teacher then can operate within that perspective to help the student follow along and gradually adopt The Right View. This often works better than forcing an immature student into the mandala of fruition.