The Flashed Face Distortion effect:
At the Exp. Psych. Conference in Sydney there was a talk on this effect from a chap at Thompson's lab, where they've been testing which conditions give the strongest results.
The deviations from the norm that define each face become wildly exaggerated when seen in peripheral vision and in immediate succession to faces that deviate in other ways, so that (for instance) a higher-than-average forehead becomes a vast projection screen that only Substance McGravitas would find enticing, and so on. The sequential contrast of shape and colouring brings out the Innsmouth Look in otherwise-unexceptional faces or turns them into Mannerist grotesques... evidently sequential contrast phenomena work more strongly in peripheral vision. This all has to do with norm-based facial coding, which featured heavily at the conference, though no-one ever explained why they singled out Norm.
Only a very bad person would consider taking various US Republican-party primary candidates and compiling their photographs into a GIF, flashing at a rate of 2 to 5 per second, to be seen 6.5° away from the visual fixation point.