How to Make a Caller ID Picture Larger on an iPhoneby Adam Brown
The Apple iPhone enables you to link a photo to an existing contact saved on your device. This photo becomes the contact's unique caller ID picture. When you receive an incoming phone call from this particular contact, the photo is displayed for easier and quicker identification. If the photo has a different frame size than the iPhone's screen, black bars may be displayed whenever your contact calls. However, you can enlarge the photo so that it fills the entire screen.
Access your contacts and select the name you want to edit the Caller ID of.
Tap "Edit" in the top-right corner.
Tap the existing photo associated with the contact and select "Edit Photo" from the pop-up menu.
Place two fingers on the screen and motion outward to enlarge the photo. Frame the photo to your preference and tap "Choose."