This is a DI working in the field instead of on the road. You can see the yellow paint job, light, and the extended clutch lever (actually another lever, bent over at an angle to the normal lever). If you look close, you can see the dual power control (in my copy it is a better quality picture, but I can't scan very well, it seems.)
Here is the same photo, yet it is retouched to look like a styled D. Look at the front axle, the flywheel, the corn-picker, certain corn-stalks, the man driving the tractor. Strange, Ain't it? Actually, if you look at some of the early advertisements of the styled series, the practice of retouching photos was common, because the final design might not have been nailed down yet. It is hard, though, to find the original photo that was "Fixed".