It is just an optical illusion.How the hell that is supposed to prove you are stressed beats me..If they were physically moving about then I might get stressed...I can't watch anything like this for long because it can trigger a migraine.
Mind these are gentle compared to the OP ART of the 60's.

Anyone wearing thin stripes can affect me.It's also the reason why I never collected any Bridget Riley work..
http://www.sma.shs.nebo.edu/swap/oapopacts.html
http://www.f-lohmueller.de/pov/im_bn3.htm
Get some computer generated op art here.
http://www.popartuk.com/general/comp...256-poster.asp