As promised in its teaser from a few weeks ago, Xiaomi has become the first manufacturer to release a smartphone with Samsung’s crazy 108MP image sensor inside. The newly announced Xiaomi Mi Mix Alpha 5G concept phone uses the ultra-high-res image sensor and a wrap-around “surround screen” that is a sight to behold. The key feature for photographers is, of course, that image sensor. The 1/1.33-inch 108MP ISOCELL Bright HMX sensor uses Samsung’s “tetracell” quad-bayer design that bunches pixels together…