WEMaher The top line is just this: a top line. It is not a folder, this just part of dialog structure, it is not supposed to do anything.
In order to find out what is happening with your removable drive, you need to open Library locations dialog and check it there. It will show it’s status, how many files are indexed, etc. If there are no files indexed yet on that drive, then it is totally normal that it is not being show so far. It will only appear after some images on it will be scanned.