Here is a brief analysis of this device, it seems that the difference between iPhone 4 and iPod Touch that it has the opportunity to call, Take a closer look reveals that the new iPod Touch also has a different camera.
In the iPod Touch specs in the official Apple page, the rear camera resolution will be 960 x 720 pixels, which mean that it will be 1.0 megapixel. So there will be a big difference between iPhone 4 with 5 megapixel and the new iPod Touch with 1 megapixel camera.
Among other things , the iPod Touch is about two millimeters thinner than the iPhone 4. More than 1 megapixel camera would have certainly taken more thickness, especially considering that the iPod Touch is also included with a front one.