It’s new evidence that cows are capable of what we (humans broadly) previously thought them incapable of. It’s important because it’s a concrete indicator that there’s more going on in cow brains than humans have generally assumed.
As I said, perhaps this is surprising only because we understand brains overly mechanically. As if it's assumed that there's a hard "can/can't do" switch for particular mental actions, while in reality any ability may be a result of various factors within the individual brain and outside of it aligning together (including, of course, the cow in question being a pet, so having a very comfortable lifestyle). If people can vary wildly in their mental abilities and inclinations, why wouldn't animals?