This is a shot of the "secret block" that makes the illusion work (for me).
step 5 of 10
Background: enlarge the source image to fill the canvas. Apply polar coordinates two times
step 6 of 10
step 7 of 10
Gaussian blur applied
step 8 of 10
Color overlay
step 9 of 10
Reactivate all the block layers and apply levels, color fill, hue / saturation.
step 10 of 10
(Forgot to add this) made a thick "line" with rectangle tool to help align the blocks. Just rotated the "line" each time to suit the direction of the overall triangle shape.