The /root folder is the home folder of the root user (the administrator). That is, you (as a normal user) cannot see the personal stuff of the administrator which is fine and is the right thing to happen. Now, the root partition is just /. I guess you just misinterpreted the meaning of the folder /root and the root partition /.

The root partition (and corresponding folder) is called /. So if you need to see your file system you just need to type / in the locations bar.

Also, notice there is an item (in the image you uploaded) which reads File System under DEVICES. Click it and see what reads on the locations bar.