Xiaomi Mi MIX 4 will not be shown on December 10th. They will only tell about the date of the announcement. The presentation will take place at the end of December.
60, 90 and 120HZ
Under display front camera:
12MP + 2MP
108MP + 20MP + 12MP + 5MP
Also, Xiaomi will strongly deny the imminent release of the new MIX in order to surprise at the end of the year.