The Mate 8 is an as-yet-unreleased 5.7-inch flagship device but the Mate 7 gives you some idea of what to expect. The Nexus 6 followed this pattern, essentially tweaking the work Motorola had already done on the Moto X.
One difference could be the CPU: the next Nexus is rumoured to use the Snapdragon 810, whereas Huawei's own Kirin 930 is slated for the Mate 8. There have also been various claims that LG is going to make a smaller Nexus alongside the Huawei one.
Kirin on regardless
A separate report this weekend suggests that Huawei is busy working on its own mobile operating system too. Dubbed Kirin, it would give the company more flexibility to deviate from Google's official Android releases.
Huawei's current devices run Android with a bespoke Emotion UI overlay, but Kirin would be something completely separate - apparently it's been in development at the Chinese firm for three years.
Own-brand mobile OSes are a hot topic right now, with Samsung pushing Tizen, OnePlus releasing its own OxygenOS and Cyanogen saying it wants to steal Android away from Google. Taking on Google is a daunting challenge, but it seems there are plenty willing to take it on.