It is really interesting to me about the difference between a miniature horse and a pony.
I couldn't tell you what those differences are, but having worked with horses, ponies, and miniature horses from time to time, a miniature horse in EVERY way is a horse ...
if you were to stand a pony next to a miniature horse you can see the difference, and then the similarities to a regular horse and the mini.
Your pictures of Rosie are so right on - - horse!
it is just very interesting.