Well, I assume she's verifying that whatever she is looking for is there, and those that don't have the markings get set aside into another pile. I'm not watching the feed but I bet there will be hours that go by of nothing but "valid" ballots so it would appear to us that nothing was being caught... until the batches of fraudulent ballots start showing up and even then it would still appear to the viewer that nothing was different because those ballots all came in the middle of the night so they'd all be in the same group. Where the DS was truly stupid, they didn't slip the fake ballots throughout the day, it was one massive dump.

I'm positive it isn't a scenario where it's one ballot Trump, one fraudulent ballot Biden and so on and so on. There will be tho, throughout the voting day that intermixing of normal paper ballots Trump v. Biden but not with fraudulent ballots.