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/Rename If 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