When you used the Location tool it is a bit misleading. The Dialogue appears to be moving the Pictures folder but in fact what is does is move the contents to the new location, i.e. you wanted E:\Pictures but everything is now in the root of E:\ Because
it is actually the drive letter it cannot take a label.
Using the same location tool you will find the Restore Default button, this will re-create the
userprofile\Pictures folder. You will need to copy the pictures from the E:\ drive back into the right folder.
Then use the Location tool again but this time make the Pictures folder 1st on the E:\ and relocate into that.
To get a better view of the folders that make up the User Profile including those that have been moved press the Windows key +R and in the Run box type
%userprofile%, This will open an Explorer box that shows all the folders that make up the profile irrespective of where they actually are located.