There was a guy who lived in NYC a while back that had a fold-up (bag) trailer he kept in his apartment that (if I remember correctly) towed a moped behind his C-10 for some reason. I'm sure you could tow a light-weight dirtbike or DS if you really wanted to. Just consider the overall weight. That looks to be a super light weight trailer (custom built?). Look at the amount of gear on the bike. Notice the boot storage on the DS?
I would think you would have to be really careful unloading so you don't knock the tow vehicle over.