With orders now starting to arrive to those who ordered the new Google Pixel or Pixel XL, Google has posted both the factory images and the OTA updates for both phones on the Android Developer website. This follows the trend that the company has had the last two device rounds (Nexus 5X/6P and Marshmallow & Nexus 6/Lollipop). This means that, like the Nexus lineup before it, the Pixel lineup will have images that those who want to manually update their devices can use as soon as the images are released instead of waiting for the standard over-the-air updates.
For both the Google Pixel and the Pixel XL, there are three images of Nougat 7.1 available: NDE63H, NDE63L, and NDE63P. All
three are dated October 2016 represent the incremental updates to the devices that has been going on even prior to their release.
Finally, if you have ordered and received a new Google Pixel and you are new to Android, there is no need to do these manual updates. Like iOS on iPhone and Windows 10 on Windows Phone, updates to your device are sent down automatically to them and they only require a restart on your part. These images are for those who have a comfort level and understanding of the Android SDK
For those who do want to do the flash update, you can download the Factory images here from the developer site at Google.