It allows you to copy a screenshot to the clipboard, either by default or it prompts you with a menu asking whether you would like to save to photos or copy to clipboard. There is also an option to do both. Greatest tweak I've found in a while! Most of the time when you screenshot something it is to share with someone, I can't count how many times I've screenshotted something only to copy and delete it. I actually thought of the idea on my own and searched for it hoping someone else had, great minds think alike! I really wish Apple would think like this.