Complex sentence: The children's grandmother has affections for the man who lives across the street, Mr. Wienburger, and there is a running gag in that his face is never visible; the viewer seeing either just a silhouette or the back of his head.
Split into simpler sentences: The children's Grandmother has affections for the man who lives across the street, Mister Wineberger. This is a running gag, in that his face is never visible, just a silhouette or the back of his head.