A more or less common joke in 2013 is to refer to an imaginary Hate button, or a -1 button, in reference to the ubiquitous Like/+1/Favorite buttons that appear to adorn every single thing in the world wide web these days. I think it's an idea worth thinking about for a moment.
What if you had Like and Hate buttons for pictures, and what if you bubbled to the top pictures for which: the sum of likes and hates was large relative to the number of views, and the difference between number of likes and hates was small relative to their sum.
What results is pictures that lots of people react to, sufficiently to mash a button, but which people are more or less evenly split on. Many like it, many hate it.
I dunno about you, but I think I might like to see those pictures,
 Yes, I know that some places have up/down voting buttons, but I'm pretty sure the down votes usually make the object trend toward less visible, and ups make the object more visible, which isn't at all what I propose here.