To Copy an Image to another Folder
1. Click on the image, and select Move/Copy selection from the Selection menu.
Move/Copy

2. Note the large blue dialog window that appears, with a mini view of the selected image at the top left. Select Copy to from the pull-down box.

3. Click on the name of the folder you want the image to be copied to.

Continue/miniview/RenameIf you have Rename checkbox checked, as shown at the left, you'll be prompted for a new name for the image.
If you have the Continue box checked, the image will be replaced by another one when the copying is done.

Note: before you begin this process, you'll need to choose (and/or make) the folders you want to assign images to. Do this by Command-clicking any of the folders that appear in the dialog box above.
The standard Mac dialog box will let you find the folder you want to use.

Copy to

Instead of copying the image into the selected folder, you can use the bottom item of the context menu (see above) to make an alias there instead. The advantatge is that you save a lot of disk space.

Click here for another feature of this Dialog Box.