Documentation 2.2.0:
Adds a mosaic effect to the display. Valid x and y values are between 0 and 3, inclusive.
However, the function actually works with the power of 2 using those values. So instead of passing 0, 1, 2, 3 I have to pass 1, 2, 4, 8 (0 works, too).
Tested only in the simulator and the C SDK.