The Contract Land hasn't officially appeared in the game, so Bai Wei had never seen a person from the Contract Land. But when its envoy appeared, Bai Wei recognized it immediately.
The reason was simple: Bai Wei sensed an extremely familiar aura from the envoy, which was the power of the Corpse Blocks. Of course, this didn't mean the envoy had Visas's Corpse Blocks; it just meant he was in a state influenced by their rules.
And this rule was naturally the "Contract" from the Nameless Finger.
In "Desecration," the Contract Land never officially appeared, but perhaps to drum up interest for a DLC, the developers released some of its setting. Among the key points was that the Contract Land was established with a rule from a certain Corpse Piece of Visas, and this piece was the Nameless Finger, and the rule was the "Contract."
