When you created a "Junction", it will behave like you have all the files in that particular folder. However, the files actually located at other place (target folder).
There is no way to know whether the folder you look at is a "directory" or a "junction" using the windows explorer. There are alternatives however to differentiate them.
One way is by using the "Command Prompt".
1) Change the directory to the folder/directory of interest
2) dir /a to list all directory/junctions
3) dir /al /s to list all directory/junctions in the directory or subdirectories
Thanks to [source]