Sun Casted A Prism Only On Part Of A Cloud?

This happened near my hometown the other day on the Mississippi Gulf Coast. I’ve never seen it before, and can’t really figure out how it could happen unless our sun is way more local than THEY say it is….obviously it is. It was hard to drive & film. The video doesn’t really do a lot of justice for the prism colors casted on the cloud. With my live, naked eye, I saw every crisp color of the beautiful prism rainbow only at the tip of this cloud. But it’s not as impressive through the camera lens.