Libraries in Windows Explorer can be confusing. However, adding a folder to the Pictures library can make it easier if you’re always navigating to the same places for images not stored in My Pictures.
Like favorites, “adding” a folder to a library doesn’t actually move it. It just links it, making it easier to find. Right-click on the Pictures library icon in the Navigation pane of Windows Explorer and choose Properties. Then, click on the Include a Folder button. Navigate to where you store images to select. Then OK. Your pictures are now a click away!