It wouldn't take much for that reality to be distorted and end up leaving some people with the impression that Amazon has security cameras watching who votes. That's going to suppress the vote and potentially alter the outcome.
Just look at this thread and how much confusion over what the cameras are recording.
> During this portion, the NLRB will read off each voter’s name and both sides will be allowed to contest ballots, likely based on factors such as whether an employee’s job title entitles them to vote or an illegible signature. Any contested ballots will be set aside.
The union lost by 2 votes. The election results were later thrown out because the company had engaged in illegal electioneering, but by the time this happened the company had fired several union organizers (also illegally) and the campaign lost steam.
It does when they have the ability to undetected break into the room where the ballots are and replace ballots. The crime is easy enough to plan. I'm not sure if security is good enough to stop it or not.
It says that the cameras would "keep an eye on the ballot boxes in the off hours between counting" which seems... perfectly reasonable to me.