The Pixel XL 2 will reportedly have multiple display profiles as well as an always-on-screen, along with a couple of other new features that can't currently be found in the existing Pixel and Pixel XL. According to a new report from XDA Developers, citing an unnamed source, the Pixel XL 2 will allow for users to change the screen's sRGB mode over to a "Vivid Colors" option if the user desires. This sort of display customization is not generally found in many Android devices which run on stock Android software, though it's not uncommon for it to appear in quite a few handsets which have extra features due to an in-house UI developed by the phone manufacturer.
In addition to adding the Vivid Colors mode to the display's sRGB options, it's also stated that this particular change will be transported to the standard Display Options menu inside the Settings as opposed to being present in the Developers Options menu. It's also been noted that the user interface will be moving back to the darker default theme that was seen in the earliest versions of the Android O Developer Preview. This is a relatively minor new change to expect but it is worth mentioning as some users may have found the lighter default theme to be to their liking. The rumor states that Google may debut a new system font with the Pixel XL 2 (which would also likely appear on the Pixel 2), moving away from the current font used on last year's Pixel and Pixel XL.
As for the Always-on display, this isn't entirely new information as it was reported back on July 6th that Google seemed to be working on adding an Always-On display to the Pixel lineup for the new device. That said, details of this feature showing up in a new rumor would suggest that this may actually be a true feature to expect. The report also reiterates that the Pixel XL 2 will utilize a squeezable frame similar to what can be found on the HTC U11, a detail which was just leaked out a couple of days ago. Expanding on this feature though, XDA reports some potential uses, with Google planning to add some additional functionality on top of the standard function of launching apps when a user squeezes the frame, such as the ability to silence incoming phone calls, and the ability to easily adjust the pressure sensitivity for a lighter or firmer squeeze. While none of this information about the device can be confirmed just yet, the Pixel XL 2 seems like it's starting to take shape more and more, and additional details are likely to surface as it gets closer to the suspected announcement date of the first week of October.