That's not really how 👀 is used these days among the young folk, but I wouldn't expect a random Canadian farmer to know that either.

I don't think that a thumbs up emoji should be a valid signature. The farmer was responding to "please confirm flax contract" and the thumbs up emoji really could mean "I've seen your text and will look at the contract to confirm/deny soon." Although the article did also mention that the same type of acceptance had happened previously with this farmer where the contracts were treated as valid and fulfilled so the farmer is probably disingenuous with their argument.