Thanks to Eric for this. He says:
At Ligoneer Days Parade.
2013 is the return of mini pony pictures from the annual Fort Ligonier Days Parade after not receiving any in 2012. 2011 saw this picture and 2010 was the first year on PSAMP with multiple pictures (1, 2). The mini pony above from this year's parade looks like he might be in one of those previous submissions, too. Or it's one of his cousins. Either way, awesome mini pony family.