Compared to the early prototypes that Huawei showed the release button for the screen has been redesigned. It got an orange highlight to make it easier to spot and serve as a design accent.
The company previously delayed the market release quoting durability concerns shortly after Samsung was forced to recall its own Galaxy Fold. Back then Huawei committed to running more tests on the Mate X and make sure that it will only deliver the product when it's up to standard. We are yet to see what changed, but it can't be long now.