ASCII-Pony is a screenshot information tool, but it does not display distribution logo like screenFetch, ponies from My Little Pony: Friendship Is Magic (2010-) instead, which is an animated television show for children.
The script is even named systempony, how fitting to this pony overloading tool. You pony it for screenshot, pretty sure its a verb. As for what it actually mean, I have no clues.