That's some mighty fine green-washing going on there, as well as creating the illusion of a "premium" product for which they can justify a higher price.
The self-reported "low carbon" certification doesn't seem to include the GHG produced by growing and transporting the feed to the cattle, the cattle to the abattoir, running the factory, distributing the beef, though, does it? I could not find those numbers anywhere.
It also elides the other issues with beef, such as water and land-use. A kcal of beef is going to cost hundreds more gallons of water to produce than a kcal of vegetables. What about nitrogen run-off into ground water from feed lots?