Explaination of Mr Angry and Mrs Calm

For those who have walked away from the comp screen just to find out why does the face appeared to swap, let me slightly explains how this work.

Firstly, both pictures actually contains 2 faces each.

The ones we see up close are in finer detail, whereas the other which we see from afar are actually blured.

Much like a high pass filter and low pass filter, our eyes can only see the details when it is sharp and clear. Therefore when we are nearer to image we see the face which have finer detail. However as we move away, the face with the finer detail becomes fader due to the diffculty in seeing the fine lines. At the same time, the blurry image sharpen when we walk away from it. Thus condensing the blurry lines into a sharper image.

A easier way to test this without walking away would be to remove your specs and put them back on again. Works for those who are about 300 and above I guess.