I am taking a risk of getting my own topic very off topic here 
But I want to reply to your post, since I think I can give you some insight on it.
What he was describing is something you will only be able to do with practice, at least that was the case for me. As your brain develops it will start to work.
My own experience:
One advice: Take notes. Notes about what works for you and what not. I have done that and it is of extreme value.
Sometimes my whole memory process would just be garbled, images would become shaky and I would have a hard time visualizing at all. Through taking notes and thinking about the process and what works for me and what not I have made some immense progress.
Let me explain: When I first started I was not able to do any movement in my palaces. I would just not be able to see it.
I could not exaggerate, make things big…, I could not visualize something memorable outside the ordinary. Very frustrating.
What worked like a charm for me though was:
- Visualizing familiar itmes. Everytime I would have a hard time visualizing I would tell myself literally: “familiar stuff, familiar stuff.” and I would get better at visualizing.
- Viewing Loci as pictures. / Viewing everything as a picture.
This worked really really well. As I realized that I could not do any exaggeration I just focused on seeing one picture at a time. So I literally walked through the palace and saw each locus with the memory object in it as if I was taking a picture of it. By “taking a picture” i mean that I look at a loci only once and try to see the locus and the object in there together. With this I jump from locus to locus. Bam, picture, bam, picture, bam picture… One advantage of it is that you can do stuff very fast this way.
Doing that for a longer period made me very good in it. I could see everything with great detail and in fact sometimes I could not even tell the difference between a real memory and the one I visualized.
But still I could not do anything else like movement.
As time progressed I found that doing the picture thing of the Locus and then doing a close-up picture of the locus worked even better. So what I do now is that I walk by locus after locus with my “taking picture” method, that is to see it as a whole image and then I visualize another picture. A close up of the locus.
And you know what’s interesting now?
My brain will now just automatically come up with texture, lighting and surrounding of the “zoomed in locus”
What do I want to say by that? These are tiny loci I have never seen before. These are not real memories in my head like the others I have mentioned before.
My brain now just automatically comes up with it.
For example in a palace I have only been once I roughly know the layout but now I can just zoom in and have a very vivid locus present. An unreal one I do not know. My brain just came up with it.
The same thing applies to holes in my palaces.
Is there a place I can not remember exactly? No problem- just visualize something from your memory there and the hole is stuffed.
So in your case, don’t overcomplicate things.
Visualizing is a work in progress.
Remember that I said I could not do animations or movements at all in the beginning? I have been practicing for 2 years now and I only now start to being able to do animations. PAO was a pain for me when I started.
Take your time, do what works great. Get better at it in just memorizing stuff with it.
Every brain is different.
Take notes, analyze but don’t overthink things.
Only conclude from things that you have tried for a while. Not stuff that just worked well for a day or two.
Relax. If you are not relaxed it will not work and you get brain-tired.
Overthinking and not being able to let it happen were the 2 barriers for me.
Use what’s works, and as your brain learns how to do other things, try to develop it and see how it goes.
Not every advise here on the forum might work for you.
Not every advise here on the forum might work for you NOW, but maybe in the future.
Your brain is unique. Get to know it and develop what works great. Be amazed when all of a sudden it does things it could not do before 
Be content with setbacks.
Sometimes your whole visualizing process will start to crumble and you are thinking: “why in the world does it not work anymore? Why in the world do my memories not stick…?” Usually this is the case when I am a) stressed b)try to focus too hard, or am not using my personal memories c)am tired d)have not drank enough water or e) am about to enter a breakthrough in my process and am about to get even better. d)sometimes, I do not know the reason.
And I have to be content with it.
So keep trying. Put the energy you have more in practicing than in thinking about the process.