It just dawned on me, the neck-thingies that Celestia and Luna wear, they're actually harnesses or yokes, much like the one Big Mac wears but obviously a lot more... decorative.

Going with what was said recently about them being inspired by the Old Norse Skinfaxi and Hrímfaxi, these harnesses are obviously symbolic of how they pull the sun and the moon across the sky, like they'd pull a chariot.

Does that make sense, or did my mind just melt down or something?