Just what is Huawei up to on March 20? In a teaser posted online, it seems the technology company is going to announce a device with a rollable screen, which expands from one size out into another.

The Pura X is also the first phone to run the new Harmony Intelligence AI assistant.

The outer display is a 3.5-inch square screen that lets you check messages, take calls, or snap photos without unfolding the device. The Pura X is Huawei’s first phone to completely ditch ...