Right, last night I tried a relaxation technique in earnest for the first time. After a bit, I started seeing things “in my mind” that seemed to be unrelated to any string of thoughts (since I was concentrating on my breathing) and to each other. For example, I saw a few unfamiliar faces and even a scene in black-and-white that looked WWII-related. Bizarrely, I even got some obscure memories back that I hadn’t thought about in years. My question is: Was this what is called HI?
Well the definition of HI is
So the things you saw sound like HI to me.
I always see things with my eyes closed. How can you tell the difference between HI and what you normally see when you close your eyes?
What kinds of things do you see when you close your eyes? When I close my eyes, I see stuff that looks like I looked at the Sun too long, except they move and swirl and stuff, even when I am not trying WILD.
That happened to me last night. I was trying WILD and then I saw in my mind a first person view of me, I guess, going through my house pretty fast and going right through doors even though I didn’t try to think of that. I snapped out of it in like 2 seconds though.
Oh, I see all sorts of things. 
closes eyes
A tank making a turn. 
Must have been from a computer game. I also see wolfs, orks, anything really.
It’s all kind of blurry though. I suppose HI clearer?
Yes, what I saw was much clearer than the stuff I see when I close my eyes during the day. Not only that, but it had almost nothing to do with my daily life. Well, I guess it’s hypnagogic imagery since it fits the definition.
Yea, ok. The line is still kind of vague though. 
The things I see get clearer in bed, and it’s always random. I can manipulate it though. It’s kind of fun.
Oh well, doesn’t really matter what’s HI. Perhaps I’ve never seen it, and will recognise it once I do. 
I was attempting MILD the other day and I also saw faces I did not recognize.
HI in my own words would be: A screen saver you are seeing in its entirity. The lines jumping moving, shapes, blobs of light and dark, a spectrum of colors dancing everywhere.
very trippy