No pic handy, but there are threads that show good examples. It almost always looks like a whitish, dull spot on the clearcoat. It comes from getting the paint too hot when using a rotary. Note that it's a pretty extreme example of damage, you can do a much less serious damage and still ruin the paint by thinning it too much. The only fix is to repaint the area.
NOT burning the paint is pretty easy. Give thought to your speed and technique and pay attention to what you're doing. I've never burned paint and I'm not some zen master when it comes to the rotary I just use common sense.