Golf Cart Bike Trailer?

On the Mount Vernon Trail, I came upon this interesting looking bike and trailer combo. The bike seemed to be a Dahon. The trailer apparently was a Burley of some sort.  It seemed odd that the load was oriented vertically instead of horizontally. I would have expected it to wobble but it didn't and he was going pretty fast-ish (well, faster than me) for most of the time I was behind him.

The picture was taken on the way up to the stone bridge. I was going fast because I had stopped to get my camera out of its frame bag and Mr. Bike Trailer left me in the dust. I caught him on the little, bumpy climb to the stone bridge. .

As I look at this now, I can see a pretty decent alternative to a golf cart in the making here. Bike golf, could catch on. Note the rider isn't wearing a helmet because golfers are risk taking maniacs.