Theoretically, if the bubble was clearly marked but not fully filled (maybe a checkmark instead of filling the bubble), the human looking at the ballot could make the intention of the voter more clear by filling in the rest of the bubble.
EDIT: I actually found another post that attempts to explain it here.
There was a woman in the longer video that is copying things from a ballot on the left onto a ballot on the right.
If that's what's happening, though, it is still insanely rife for exploit. This is scary, scary stuff.
Theoretically, if the bubble was clearly marked but not fully filled (maybe a checkmark instead of filling the bubble), the human looking at the ballot could make the intention of the voter more clear by filling in the rest of the bubble.
EDIT: I actually found another post that attempts to explain it here.
There was a woman in the longer video that is copying things from a ballot on the left onto a ballot on the right.
If that's what's happening, though, it is still insanely rife for exploit. This is scary, scary stuff.
All of these should be electronically tallied and copied prior to human examination.