For much of this material, I doubt most people without direct experience are going to be able to see whats going on. Thus I don't see too much point to video.
However, for this particular mechanic, what I'm referring to can be done in an internal way, but the following video, is more done in a "precursor" way. That is to say, I am still using muscle to raise the shoulder/arm, just not relying on the shoulder. Eventually, you don't want to rely on muscle so much, but use Sigman's suit. Thus I would not call this demo an "internal" arm raise, rather one with passibly good mechanics. Even now, when demonstrating this, you will see my body moving in certain ways, but don't talk about in the video other parts of my body being tugged as that arm raises.
Making video's is tough. I really appreciate your efforts to do so. Last night I was standing in front of the mirror with my shirt off trying to figure out how you could show the shoulder " not activating" and it was pretty hard. But I think this is still a good avenue to try, and possibly as we all understand how to show things better, we'll be able to make better videos. Either way I appreciate your effort!
So, there is no doubt that it's difficult to see what is going on. But most of what I can see is that you are keeping the shoulder from 'raising'. This raising shoulder is a problem in lot's of martial arts students, and is caused by unnecessary activation of the trapezius muscle. You do a good job or relaxing that muscle on your arm raise. However, if you touch your deltoid while raising your arm, no matter how you do it, can't you feel your deltoid activate? By rotating the arm as you lift, you can change the activation between anterior, lateral and posterior deltoid, but they should still be firing to some degree.
While I was playing with this yesterday, I found several interesting things I could do. If I took a big breath in while raising my arm, I noticed that the expansion of my chest made my shoulder arms start to raise (because my arm was resting on my ribcage) and if I slowly added shoulder pressure from there, the activation of my deltoid was very subtle, and much harder to notice. However when my arm was extended out 180- I could still feel a hard deltoid holding my arm up.
Again, I'm struck by the idea of 'imagery'. Using a good image, like an expanding balloon may help me better use my muscles. But I still feel it's impossible for me to raise my arm out to the side without engaging my shoulder muscles.