On Reddit, author says "The preview is shown at 20fps for a 3x scale image (90x90 pixels) and 50fps for a 1x scale image. This is due to the time it takes to read the image data from the sensor (~10ms) and the max write speed of the display.", and adds that optical mice motion tracking goes to 6400 fps for this sensor but you can't actually transmit image at that rate.

https://old.reddit.com/r/electronics/comments/1olyu7r/i_made...