Probably couldn't afford to replace the nice big tires. Mud tires wear way quicker than most would think, and hes rocking cheap steelies, so I bet its a money issue that come up after he put the lift on.
He might have thought he would have to replace them as often as regular tires, and then after seeing how quick they went bald, he downgraded to steelies and regular tires. It would be an understandable but expensive mistake.
Seriously, as good as mud tires look, they go bald quick and they are expensive as hell in larger sizes. That plus the road noise is just atrocious. Stuff you might not realize until you own them yourself, and then you're stuck with a jacked truck with small wheels.
Road legal ness, would say winter rated but the grass is green, could have gotten a damaged rim or tire. It’s likely something that needed a different set of rims though.
Or it's at a shop, and they pulled the fatties off to change the tires, ran into some issue, needed to free up the bay waiting for parts, so threw on a set of something to be able to move it.
I had a little Mazda 4x4 that looked like this for a week or so, after I recovered it from being stolen. I figure they put the little wheels on it just to drive it away from wherever they sold the nice wheels.
My nittos are pretty aggressive 35's and I got 65k out of them. Only replaced because one of the tires wore a bit faster and got to the wear bars, honestly could have replaced just the two rear tires but went for the whole set since it's less of a PITA to go to the shop just once