A fan of the University of Oklahoma Sooners gives the "Horns down" side to mock the rival team, the University of Texas Longhorns, during the 2007 <a href="//commons.wikimedia.org/wiki/Red_River_Shootout" title="Red River Shootout">Red River Shootout</a>.  The taunting hand gesture is an inverted <a href="//commons.wikimedia.org/wiki/Hook_%27em_Horns" title="Hook 'em Horns">Hook 'em Horns</a>.  Note also the upside down Longhorn logo on the t-shirt.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/15942874@N00">Derek Green</a>
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/15942874@N00/1534614829/">DSC_3805</a>