Before an update is released to a smartphone, clearly there is testing that needs to be done on the update before it is released to the public. This is why alpha and beta builds exist where bugs and issues are caught before they affect too many users. We have seen in the past how some updates can end up rendering devices unusable, which is why testing is important.
Unfortunately it seems that Google might have accidentally seeded some Pixel XL owners a dogfood build of an Android update. According to reports, it seems that some Pixel XL owners have received an Android update that has been clearly marked as “confidential internal only”, meaning that this update was aimed at Google employees and not meant for the public.
As for what’s inside this update, it seems that Google might have caught a break because while the update weighs in at 62.3MB and has the build number N2G470, users who have received the update are reporting that there aren’t any visible changes. There could be some internal changes but as far as user-visible changes are concerned, there does not appear to be anything different.
It is also lucky that this update has not caused any Pixel XL devices to malfunction, or at least we haven’t heard any reports. In any case we expect that this update should be released to users in the near future and hopefully there’ll be a changelog that shows us what we can expect with it.