Starting with what might be the most interesting new discovery: Portrait Lighting. This feature appears to be an enhancement on the iPhone’s Portrait mode effect for creating dSLR-like shots using depth by simulating different lighting effects.
Portrait Lighting, which we believe will launch in beta similar to Portrait mode last year, supports Contour Light, Natural Light, Stage Light, Stage Light Mono, and Studio Light. It’s possible this Portrait mode enhancement could be related to the flash when shooting.
Also present is new video recording resolution and capture speeds:
1080p HD at 240 fps 480 MB with 1080p HD at 240 fps
4K at 24 fps (Footer) 270 MB with 4K at 24 fps (film style) (HEVC Footer) 135 MB with 4K at 24 fps (film style)
4K at 60 fps (Footer) 450 MB with 4K at 60 fps (higher resolution, smoother) (HEVC Footer) 400 MB with 4K at 60 fps (higher resolution, smoother)
We’re also seeing evidence that the OLED iPhone will feature a True Tone Display for white balancing like the iPad Pro lineup. As for the new resolution, we believe we’ll see 1125×2436 based on this firmware.

Update: These are called Animoji and will use facial tracking and your voice to create expressive animated messages.
And there’s also clues about how the power switch (called the side button and not lock button) will be used to interact with iOS without a Home button. For example, double-clicking the side button will show Apple Pay cards and passes just like on the Apple Watch. You can also press and hold the side button to invoke Siri.
This new side button method is also tied to new Accessibility settings for adjusting the speed of the double and triple click, enabling Type to Siri, and even using Face ID to “check to see if you are looking at your iPhone before dimming the display, unlocking, or lowering the volume of alerts.”
Confirmation on a previous rumor:
The OLED iPhone is also expected to totally ditch the concept of a Home button in favor of a full screen experience and a dynamic area denoted by a line at the bottom of each app.
https://twitter.com/stroughtonsmith/status/902978400637345794
More details on a (minor) AirPod revision, small iOS 11 details (including the Face ID setup animation), and a new LTE Apple Watch can be found in the article.