Another version is "Is your father a glazier? Does he make windows, for you stand in my light and expect me to see through you?"
If the father was a good glazier, his son would be completely transparent, like glass is, but since you can't see through him, the father must've been a bad glazier. This shouldn't be taken literally though, the father is probably not a glazier at all, but it doesn't matter. "Your father was a bad glazier" is just a nicer way of saying "you're not transparent, you're in the way, please move."