its tumblrs april fools joke but its a pop up video and it could really scare people (it scared me) plus its full screen please tell everyone!!
even if you arent triggered by videos randomly playing full screen the video itself could trigger people. phobias of motion, skin, nails, space, dogs, shaking, scopophobia, bare chests, heights, repetition, etc. could be triggered by the video
please be safe
How I imagine these people doing anything.