They're just cosplay horns, it doesn't matter ultimately. At the very least, with cones, you can see the arrow shape from all angles which gets the point across nicely.
At first I was like "Wow you are being such a dick" and I still think you're KIND OF being a dick (KIND OF. not actually, but KIND OF) but all in all you were just trying to make a point but you could've worded this first comment better at the very least so it sounded more like constructive criticism and less like you picking on it. C:
Obviously someone doesn't know what a prism is. Troll horns don't have to be round at the base you know. And they could get narrower at the top to shape an arrow. Plus his horns represent a broken arrow so you can't really deny this fact :3
i never said you said it was bad. also the horns look lovely. you are just way too picky. if you cosplay this make them however You want to make them. just because someone didn't make them the way YOU want them to look doesn't make them bad and it doesn't make the person wrong. just let it be.