That trailer the tractor is on appears to be one of the Snowbear trailers with the 12" trailer wheels. They are handy little trailers with the removeable sides and ends, but mine has a gross weight rating of 2100 pounds. That tractor weighs a little over 1500 pounds without the loader according to tractordata.com. I've over loaded mine on occasion, but not routinely. I think that tractor on that trailer is more than pushing the limits.
Good eye! That is a SnowBear trailer. They are great, adaptable for many uses. With the front and rear 'tailgates' down and the tongue pulled to the extended setting (
photo) I have carried 16 ft material on it. But so far as I can tell SnowBear quit making trailers 10+ years ago.
I did some careful calculations before towing that load (photo in previous post). I'm right at, not over, the rated limit for tires, axle, trailer chassis (tare weight 400 lbs without sides, some of that carried on the hitch) + the tractor, and the Subaru's rated towing capacity. As shown in the photo I took the back way home, not the freeway, to not be a hazard to others as I poked along cautiously at 35 mph. I think the absence of trailer brakes was the only thing exceeding spec. Considering that, I never got closer than a few hundred feet to anyone on the road or pulling out. It was an uneventful slow 15 miles. But the guy who sold me the tractor had the same concern as you, he phoned to see if I made it home ok.

That photo looks like gross overload but the tow rating for this model Subaru is 50% more when sold in Australia, so I think its limited towing spec for the US is for freeway safety.
That photo above is my second Yanmar YM186D. I bought it for its loader. Previously, I brought home the earlier one (no loader) in the SnowBear:
Loading at Dave's in Red Bluff. I had the seller take it there, halfway to my ranch.
One of several stops to check tiedown chains, wheel bearing and tire temperature. No issues.
I really like the SnowBear trailer. I looked just now to see if they are still sold. Apparently not.
Found someone who posted he loads his 2k rated SnowBear to 3K with no problems. Don't be that guy.