How does the "Copy" button work for iPad photos?
The Copy function copies the photo onto the clipboard. You can then paste it into other apps, say Mail, by tapping and holding until a contextual menu appears that says "Paste". If you're on a web page, you can tap and hold an image and select "Save Image" to save it to your camera roll. But you can't use the Copy function to "paste" it into your camera roll.