Portland Horse

I was walking around Portland after cycling 200 miles yesterday, and stumbled upon this horse. Tied up. At the curb. A mini horse. There must be a story behind this, but I don't have a clue what it is. But it struck me as odd and interesting (and perhaps a little bit crazy), so I had to snap a photo with my iPhone....

ADDENDUM:
Thanks to a reader who was kind enough to send me more info about the horse project that led to the subject of this photo. You can read more details here:

http://www.horseproject.net/