To change the background of the pictures on the iPhone, use a photo editing application such as the iFoto App: 1. Import the image, and then delete the existing background using the background removal tool. 2. Replace it with a new background, or remain transparent. 3. Adjust settings such as brightness and contrast to enhance the image effects. 4. When you are satisfied, save the edited picture to the photo library of your iPhone. With these steps, you can easily change the background of any picture on the iPhone, thus adding a personal style to the photos.