But "Zeiss optics" itself was also an empty marketing boast of Nokia and other colaborators. Not that different in performance from regular third party or even OEM optics, and the phone's sensor wouldn't be able to show any discernible difference anyway.
Isn't the iphone photo software lacking somehow? Maybe it was the software? I found a big difference with that phone. Very vivid photos. Not an expert but could it have been some "contrast" setting?