I click on it and nothing happens.
EDIT: I have to click in the bottom right corner for it to work. I click anywhere else on it and it doesn't work. Even then, the frame cuts off most of the video, so I have to right click the lower left corner, click open in new tab, go to reddit and view it there. I hate reddit. Always have.
EDIT 2: And I have no idea WTF that is. I don't get it at all.