Continuity mistake: The knot of Aidan's tie is done in at least three different ways during Katie's wake: When he puts the flower down before Katie's picture, when he walks down the upstairs hallway, and when Rachel speaks to him in Katie's room. (00:12:35)
Continuity mistake: When Aidan and Noah are talking in the car, outside of Katie's house, Aidan is coloring on a blue lap tray. When Rachael comes to get him out of the car a couple of minutes later the lap tray is now green. (00:51:25 - 00:53:10)
Continuity mistake: On the way to Shelter Mountain Inn Rachel is seen driving along a lake. The water is to her right, and the forest to her left. A helicopter shot confirms that, but when we see the car from the front the forest is to her right. (00:20:45)
Continuity mistake: When Rachel gets dressed for the wake the black brassiere under her white undershirt is sometimes visible, sometimes not. (00:11:55)
Answer: At the end of the movie, she is crying about why she wasn't killed and Noah was. She vocalizes "What did I do, that he didn't?" That's when she sees the copy she made. It wasn't that she just showed it to someone else. She made a copy and Aiden watched that copy. Aiden is why it skipped her.
Almost right. It's just the copy. Copying the video makes it skip you. That's why she has Aiden make a copy as well.
lionhead
You have to show the copy to someone else as well. That's why Aiden asks Rachel at the very end "What about the person we show it to? What happens to them?"
Phaneron ★
But doesn't he have less than a day left by then? Hardly a time to relax, they need to make a terrible decision, quickly. I always had the idea making a copy was enough because of that.
lionhead
He watched the tape the morning of either Rachel's 4th or 5th day, so he should have at least 3 days left by this point. Though it appears the film was being inconsistent with the markings that Samara leaves on the tape's viewers, since Rachel noticed Samara's hand print on Aiden's arm and then his nose started bleeding. For Rachel, she got her nosebleed before receiving the mark on her arm.
Phaneron ★
Actually, you need to do both: make a copy and show it to someone else. This is further explained in The Ring 2. At the beginning, the guy had made a copy but since the girl covered her eyes and didn't watch the whole thing, he was still killed by Samara. So making a copy is not enough in itself to be spared if no-one else watches it. The same goes for Rachel. She made a copy on the 2nd day, but Becca tells her she only has 4 days left when she visits the psych ward indicating she hadn't been spared yet. It's only after Aidan watches the copy she made that death skips her for good.