Intrigued by MIT’s Marylin – Einstein hybrid image optical illusion, I made my own Bar Rafaeli – Golda Meir image, using Photoshop’s blur and high pass filters.
Hybrid images change interpretation as a function of viewing distance. Hybrids combine the low-spatial frequencies of one picture with the high spatial frequencies of another picture producing an image with an interpretation that changes with viewing distance.
In this figure, you can see the face features of Bar Rafaeli, up close, but step back a few meters and look at the image again.
Take the image that you want to be visible from far, blur it (discards all of the high frequency details), and put it in the background. Take the 2nd image, which you want to be visible from up close, put it through a high pass filter (discards all of the low frequency details), and put it on top of the background. Change the blending mode to overlay and this is it!!
View my own work: here