Alright, you’ll need to bear with us on this one. In the comics, one of Max Lord’s biggest storylines involves him hijacking a satellite-based supercomputer (turned sentient and evil) called Brother Eye. Brother Eye was actually originally created by Batman–think a similar situation to Ultron and Hank Pym (or Tony and Bruce in the MCU).
Now, Lord was eventually caught by Diana who, with use of her lasso, learned that the only way to stop Lord’s insane scheme was to kill him. She wound up snapping his neck–which was just as brutal as it sounded–but this turned out to be part of a greater and more hidden scheme where the sentient Brother Eye was able to tape and broadcast Diana murdering Lord (in what, to outsiders, looked like cold blood) to everyone on the planet, effectively turning the world on Diana in an instant.
Obviously that’s not what happens here in WW84, but the bones of the story are still the same–Diana and Lord have a final showdown in what amounts to a Brother Eye-style broadcast room connected to every person on Earth where, instead of beaming out an image of Diana ruthlessly beating Lord to a pulp, she’s able to connect with everyone and ask them to recant their wishes.