I know this is a very hard question to answer, but can you tell what kind of leather is in this picture? I have my suspicion.
I also strongly suspect this is cowhide. I don't have access to the jacket, only photos. I like the color, size and construction of the jacket and the price is very good. What I am struggling with is whether I want to spend 5x what this jacket would cost to get a horsehide jacket. I have never had a horsehide jacket. I know a lot depends on the thickness of the leather and how it is tanned, and that there is great horsehide and no so great horsehide. And, some say cowhide is very nice. What is so difficult about this hobby, is that few of us can compare different leathers and jackets in person. So, a lot of trial and error and learning by experience is involved. I have a goatskin, so I guess it couldn't hurt to buy a cowhide, and eventually maybe a horsehide too.Looks like regular cow hide to me. Does it have any labels? Look under the pocket flaps and along the interior side seams.
Many HK & China leather jkt enthusiasts are Very, very concerned about the use of HH in jkts, thinking it is better and is therefore preferred. In my opinion, If given 2 pcs of 4" square leather swatch in front of you & you cannot tell which is which, then it makes no difference whether it is HH or cowhide. So, Ｉam 100% agreed with what jeremiah said earlier.
Tell U a secret, MOST enthusiasts are too concerned about HH/ cowhide & forgot the very basics - thickness. Thickness determine the feel, texture & drape of the jacket & a IS DETERMINING factor. Some use 1.2mm leather on a worker boot & complain it have wrinkles, some use 2.5mm thick leather for belt and soft like snake skin after 1 yr of use. Some use 1.5mm goat skin in A1 & A2 & think it is very special........... so many wrong directions.
I really have no idea when the idea of HH is superior idea comes from, when & where.
Unlike jeremiah, I only wear penis skin jkts myself these days , opting for its softness - so I wear none (just kidding).