If you take a piece of cloth, fold it over and sew the sides and then cut out a hole for your face- if it fits closely the top two corners of this square sort of "Pop out". Looks like ears. It might have been that the early mountain men just wanted something warm to put on their head and came up with this style. It was common practice to crawl up, in plain sight, on big game. I think this is why white capotes were most common. A white capote and a wolf ear cap made you look a lot like a wolf. Generally they crawled to within shooting distance of about 70 yards.
Once the practice started I think the cloth was then cut to make larger ears.