About Chromebooks says it was tipped off by Brandon Lall about Atlas being used to generate bugs for the Chromium team through the Chromium Bug Tracker program. According to 9To5Google, Chromium Bug Tracker has been a reliable source for similar leaks in the past.
Whether or not Atlas is actually a Made by Google product is now a point of speculation, based on what is seen in the leaked video. Atlas does not appear to be a convertible, and the 16:9 aspect ratio is different from past Pixel models.
The other interesting clue is a placeholder at the bottom labeled "ProductName." Google does not typically brand its flagship devices in such a manner, instead going with a simple G logo.
There is less to extract from a second leaked video—these are, after all, primarily bug videos and not product demonstrations. That said, we can make out a different style keyboard compared to previous Pixelbook models, with the Atlas sporting a browish-gray color scheme.
We don't wan to read too much into these videos, though. It's entirely possible that the final design of whatever Atlas is—a Pixelbook or something else—will change between now and when it is released.