I noticed a bit of an anomaly (it may have been in the original version and I just didn’t notice it) at 00:02:58 to 00:03:06 you can see white Storm Troopers(?) walking across the Death Star (I assume they’re building it). There is a light box around them until they stop walking at 00:03:06. I don’t recall if this was in the original version or not and if so I just didn’t notice it before. I realize it’s a little late to be pointing this out so I’m going to assume it’s supposed to be there.
If it’s what I’m thinking it is, that’s a matte line. It was in the original, removed from the Special Editions (because it was unintentional but largely unavoidable in the original), and restored for the Despecialized Edition.