The photo is an iPhone 5c running Cydia 1.1.9 on iOS 7.1.1, and while these photos can easily be faked, Esser has released previous jailbreaks so we assume the photo is legit. He did shed some light on the vulnerability as well:
That iOS 7.1.1 jailbreak is not based on a long vulnerability chain. It uses a single beautiful kernel bug that goes from mobile to kernel.
We aren't sure if Esser plans to release a jailbreak, but we would assume any release would happen after iOS 8 is available to see if the vulnerability still exists.