Looks like that trailer would have a carrying capacity of about 1800 pounds, the vehicle is rated at 1500 pounds. Not sure what the tractor model but with fel and mower and whatever is hanging off the back would guess about 2200 lbs. Tires look fine, tie-down job is better than many commercial I see, trailer deck is reinforced with track under tires, the vehicle is sitting well and doesn't appear to be suffering excess tongue weight which maybe evidence of improperly proportioned trailer weight. The guy seems to know what he's doing or at least done a little research, though not legal, with careful three steps ahead type non-highway driving I wouldn't anticipate any problems.