Towing a recreational triple (truck + fifth wheel + bumper-pull trailer) is almost evenly split amongst states as to whether it's legal or not. Fifth wheel manufacturers do put hitches on some units and design them to tow a small trailer off the back. I can't speak to all laws but in Michigan, you must complete a written knowledge test (no skills test necessary) to obtain an "R" endorsement on your license and the overall length of the rig cannot exceed 75 feet.
All that said, that fifth wheel appears to a Palomina Puma 253FBS.
The 253FBS doesn't have a hitch installed by the manufacturer, meaning neither the unit manufacturer nor the frame manufacturer has rated it for any type of towing.
On top of that, most units of that size that do have a hitch specify maximum trailer weight off the fifth wheel at 3,000 lb GVWR and 300 lb tongue weight. That double-axle cargo trailer probably has at least a 6,000 lb. GVWR. Yeah, it could have been empty, but even then, it's a 2,500 lb trailer.
Not to be the tow police, but there is a lot about that setup that's sketchy.