Update: it turns out that the display is actually wrapped around almost the entire device, see new video below:
Xiaomi is teasing a new smartphone design, with a concept model it calls the Xiaomi Mi Mix Alpha. The phone uses a flexible OLED wrapped around the edges.
This is similar to Samsung's edge OLED smartphone designs which has been in production for many years - but Xiaomi is taking it one step further with the display wrapping completely around the edges.
In January 2019 Xiaomi unveiled a new prototype smartphone that uses a tri-foldable OLED display. The supplier of the foldable OLED for this prototype was Visionox, which also supplied Xiaomi with the innovative OLED displays with under-the-screen camera. It is highly likely that Visionox is also the company behind this current new flexible OLED prototype.