Unfortunately, this has not turned out to be as friendly as intended. There’s already confusion as some of the bags referred to as checkpoint friendly are simply slim sleeves or thin cases designed to hold just the notebook — nothing more — and are carried inside your regular bag. And while it’s true you don’t need to remove your notebook, you need to remove this sleeve with the notebook in it! I haven’t quite figured how this saves time. But I suppose it adds a little protection to the computer, keeping it apart from your liquids and shoes on the conveyer belt. 

There’s a second class of cases that does allow a notebook to remain in the case. They’re designed so that a portion of the bag unzips and folds off to the side, so the computer can be viewed without anything obstructing it. 

This meets the TSA requirement to allow an unblocked view of the computer; with no adapters, cords, or even a metal buckle alongside the notebook. These stay in a separate part of the bag. But you do need to unzip the bag to pass through X-ray and, whether you need to remove the notebook or not is subject to the whim of the TSA screeners, which we know varies widely. - entire post here