Xiaomi Mi 11 Ultra uses a Mi Band 5 display on the back

Now it turns out that this 1.1-inch color AMOLED display has been taken straight from one of Xiaomi’s most popular wearables - the Mi Band 5. According to ITHome, Xiaomi CEO Lei Jun revealed during a live broadcast in China that the Mi 11 Ultra and the Mi Band 5 share the same screen.
The Xiaomi Mi 11 Ultra sports some impressive specs
The Xiaomi Mi 11 ultra features a 6.81-inch curved 3200 x 1440 display, a Snapdragon 888 chipset, and 8/128GB or 12/256GB storage options. The enormous camera bump on the back houses three different camera lenses.
The secondary AMOLED screen on the back is designed for selfies but can do more

As for the secondary display on the back, it has a resolution of 126 x 294 pixels and can output up to 450 nits of brightness.
There are different use scenarios for this tiny AMOLED on the back of the Xiaomi Mi 11 Ultra. Its main purpose is to serve as a mirror for selfie shots but it can also be used to take calls, display notifications, or show you a huge battery meter to keep your battery life anxiety in check.
