The demo showed off three different handsets, with the left being an iPhone 6 Plus running iOS 10.3.2, the middle being an iPhone 7 running iOS 11 beta, and the right being an iPhone 7 running iOS 10.3.2.
Like with many recent jailbreaks, KeenLab’s seems to run off of a side-loaded app installed with Cydia Impactor. It may be of the semi-untethered nature, which means it would rely on certificates that expire and would need to be re-signed after reboots every so often, but so far this hasn’t been confirmed.
Although we must reiterate that KeenLab is unlikely to release their jailbreak, that’s not to say that someone else won’t come through in the future after iOS 11 comes out of beta. It should be interesting to see what happens following the public iOS 11 release this Fall.