I have no idea what it is and I’m not sure I even care.
Xiaomi’s doesn’t have any 2K phones, so VR has to be out. Although this is Xiaomi and their rabid fans would probably settle for highly-screendoored VR on their 1920 x 1080 screens.
Replies to the tweet are jumping to the conclusion the above design is a rip-off of Apple design.
Google I/O begins tomorrow.
Next-day update: Miguel Santos in Comments let me know Xiaomi does indeed have one 2K-screen phone: the Mi Note Pro. Somehow that slipped by me. Thanks, Miguel.
May 19, 2016 update: It’s their Mi Box for TV. Meanwhile, they will be among the first brands to offer a “Daydream-ready” (aka VR-ready) phone later this year. But that phone likely won’t be appearing in the U.S. or Europe.