Most notably, there's a fingerprint reader stealthily included on the top of the tablet -- this lines up with both Nocturne's specs and a fingerprint enrollment image discovered in Chrome OS just days ago. The USB-C port on the lower left side also matches hints of two USB-C connections (the other would be on the right side). And the screen's tall aspect ratio would match Nocturne's 2,400 x 1,600 resolution -- conveniently the same as what you'd find on today's Pixelbook laptop.
The future Google device is also expected to have pogo pins for detachable keyboards and multiple microphones for echo cancellation (visible in this image). Another tablet, Atlas, could also be in the works with a 4K display.
Provided this is accurate, there's a distinct possibility you'll see this device (or something like it) at Google's event. It would certainly make sense given recent developments. Chrome OS tablets are still comparatively new, and Google may want a Pixelbook-style tablet to serve as both an attention-getting halo model and a reference for other manufacturers.