From the benchmark description: "This version has been stripped of all of the artwork and eye candy we had in the previous version." "This is running content from a local disk, so the time to download files from the network is ignored."

So they ignore all the things the user waits for, and focus on the frame rate that can be achieved once it's loaded. Bearing in mind that the most likely use of this feature is in ads, not twitch games, that's the wrong metric.