I’m afraid you are incorrect. In both movies the arrows indicate the enemy ships and the direction they are traveling. The glowing square has nothing to do with the arrows and only indicates what section the target was successfully destroyed in. If you follow the arrows and compare them to the surrounding footage, you will find that everything is completely consistent with the arrows indicating enemy ships and their flight path. If you count the arrows, you will find they always match the number of ships. You missed shot in the ANH clip at 1:20 that shows three arrows, and they fly in distinct curves like the Tie fighters, not in straight lines like the blaster bolts.