How do breaking platforms prove a card was actually pulled from a pack?

Most don't. The pull happens on camera, but nothing links the card on screen to the card that ships. BreakersDNA closes that gap by scanning high-value pulls at the table and fingerprinting the individual card.

Video proves a card came out of a pack. It does not prove the card that arrives in the mail is that same card, because a camera captures an image of a type, not the identity of one physical object. A scan taken at the moment of the pull produces a fingerprint unique to that piece of cardboard, which can be matched against the card the buyer receives.