Once again, kinda hard to tell definitively with the rust and moisture but that looks like a bubble gum weld. Doesn't look like it was much more than stuck to the frame, let alone much penetration at all.
Does it look like the factory weld?
Has the truck been wrecked?
First impression is that the weld looks like something somebody did in their driveway.
If that's a factory weld, I'd say something was out of calibration that day.