ScrathPad files and pics

When I insert a pic from ScratchPad does this pic then become part of my project file… in other words does Scrivener make a copy of the pic or does it continue to reference the pic from my ScratchPad folder?
If not how can I make it a part of my project permanently?
Eventually I would like to clean up my ScratchPad folder but not sure how this will affect my projects that have pics from this folder.