That was in some concept art in which the focus of the art wasn't the bow and arrow. Artist probably just threw that in there for fun.
Who knows, http://www.tesnexus.com/downloads/file.php?id=19396.
I mean, BGS did say they changed some aspects of the game based on certain mods (mainly bow damage)
So maybe when we enchant a weapon with, say, fire then it would show off 'fire' characteristics. And maybe, just maybe, it can happen to bows too.
But that's just me being overly optimistic.
In either case, a mod will eventually come that makes it much, much better; IF they don't add it. :thumbsup: