The F-650 and F-750's are designed as small commercial trucks that should have small dump truck bodies or maybe flat bed for hauling other materials. They are not meant to just have a standard pickup bed on the back. They are ideal for small contractors who do not need as large a quantity of material that a large triaxle truck can carry. But of course, some people want the biggest personal truck to drive around so things like your picture are born.
Even if this were illegal (and it may or may not be), it would only be a problem for the driver if cops chose to enforce whatever the relevant regulation was. If a cop pulled this abomination over, it would only be to admire it.
Fun fact: cops in the US are not required to actually know the laws they're enforcing.
Might not be the same person, but im in murfreesboro and this truck with the same tail lights and lights in general stops at the store i work over nights at every few weeks. He comes at like 3 am and takes a bunch of photos of his jacked up truck. Ive seen him do this like 6 times in the past 5 months. Idk why he does this, but its always kinda weird.