Optical illusion

Go and take a look at this rather unsettling optical illusion our Design guy at work sent me.

Oh dear...

So. There I am, standing in the boss's office yesterday afternoon, having a serious conversation about a difficult project. When I suddenly catch myself doing Jack - the hands, the stance... About 2 seconds later I see the boss's secretary (the Orlando fan) realise it too and dissolve into a fit of silent mirth. How hard was it to keep a straight face and finish the important conversation??

Thank goodness my boss hasn't seen Pirates...