i noticed a problem adding pictures in Chrome as well. i investigated with the Chrome Developer Tools and found that the "add photo" button is popping up a dialogue around 3000px below the top of the window, with position: fixed so that it is always well below the bottom of the screen in 1080p. i used Developer Tools to change it to 50px, which made it visible for me.
actually my screen looks a little different from yours! i am missing some buttons it seems, like the chart button (that changes how the votes are displayed) up next to the "number of votes left" box. also not showing the number of votes for each candidate.