I've watched the videos in the series, and while Ni tends to disengage to the sides and Si/Ti seems to disengage down, what about disengaging up? From filming myself, it looks like a mix between Ni eyes combined with the Te head back that Robert Downey J.R. does in the Te-Ni video.
- Eyes looking up = Pe exploring (cross-contextualizing) - Eyes looking to sides = Pi searching worldview - Eyes looking down = Ji accessing compass
People don't generally look upward unless they're proactively synthesizing a new perspective on the spot. This can be something that they may not have thought about before but for which they do have the basic information to formulate an opinion on. Per example if you're asked "Just using your mind, what does your name spell if you weave together your first and last name one letter at a time?" Try it.
Going into your worldview doesn't help much in this sort of situation (looking/drifting to the sides) because it isn't something you can reference. So it's not Ni. And Te doesn't really manifest in the eyes since it isn't a perception process but articulation process (manifesting more in the voice/hands/mouth). Since we all have a Pe process all types do this periodically but generally Pe-leads do it most often.