Recently I've noticed a ton of posts getting tagged with Horse Girl which are just upper body and portrait pictures of Umamusume characters for example post #5941383 and post #5947198. These images clearly show the horse ears of the characters but not a tail or any other horse-y features.
Now, as it currently stands there is no clear rule on where exactly the line between Horse_girl and Horse_ears are, but I can't help but feel if every horse_ears post is also a horse_girl post then horse_ears becomes meaningless correct? We'd just use horse_girl and horse_boy instead. With this in mind I think there needs to be some clear guidelines on when they are used. Is cat_girl a canon tag, do we only use in on non-kemonomimi_mode pictures? Surely it's not only furry posts so how much horse-ness is needed? tail, nostrils, the dog girl barking at a mailman?