The iPhone 4's box has a large shot of the iPhone running iOS 4 on the front, and a sticker with your ICCID on the back (you'll need this number when setting up your new phone).
Need more iPhone 4 pictures? Check out Apple iPhone 4: A Visual Tour.
For more on the new operating system, read Apple iOS4: 10 Best Features.
For an overview of the early reviews, see The First iPhone 4 Reviews: Spoilers Ahead!