Here’s a preview of something from our textbook. it’s an explanation of a common reading order mistake in comics (I drew this one in a quasi-Tezuka style, just for fun):
Why did these guys get blown up? Didn’t the other guy get the code? Well, did you? Let’s see. Maybe you thought it was:
But wait, how do you know it wasn’t:
Without arrows, there’s no way to know for sure. This situation is rarely this fatal, but you want to avoid pointlessly presenting your reader with such an ambiguous situation.