Before the silent meditation Alan briefly reviews what he has already explained a couple of days ago: If the visualizations keep you awake or you just can’t visualize them, then it’s better to either settle your mind in its natural state (if you tend to fall asleep easily) or practice mindfulness of breathing (if you’re one of the poor souls who can’t fall asleep).
After the meditation Alan once again looks back first only to then venture into the practice associated with dreamless sleep. As said before, in the dream state your power of imagination is more brilliant than in the waking state unless you have very stable samadhi. What you see in your dreams then, are the effulgences of your substrate. This is important to note since an encounter with Padmasambhava or Einstein (or Lady Gaga for that matter…) is quite likely not really Padmasambhava/Einstein/Lady Gaga but your imagination of them. While real encounters in the dream state happen (more so with Padmasambhava than with Lady Gaga, so I’ve heard), you have to be an experienced practitioner to be blessed with such an event. However, just because it’s not “the real thing” it does’t make it worthless - quite the contrary, as such dreams are rehearsals or good preparation for when it really matters.
Alan then goes into the text and explains the five poisons that are mentioned from different perspectives. The poisons (craving, hostility, delusion, envy and pride) are mental afflictions. So, if you become an arhat then just vanish and all the seeds for those afflictions are terminated. However, from a Vajrayana perspective then don’t simply vanish. Rather you maintain pure vision (as well as possible) and, thus, once mental afflictions arise you see their empty nature by the power of your imagination. Consequently, you don’t terminate them, but transmute them - you see them as facets of primordial consciousness, take away all their energy and use them for your path to enlightenment. From a Dzogchen view, however, even that is unnecessary because you can also simply release those mental afflictions. You don’t have to imagine anything, and neither do you have to terminate anything, you simply view them from the perspective of rigpa.

Silent meditation cut out at 11:46