When making the bread, Thelma accidentally uses a recipe for 600 people and puts five pounds of yeast into the dough. As the bread bursts out of the oven and rises to where it fills up the whole room, it looks as if a large inflatable balloon or raft has been pumped up with air.
A dough boy is slang for an American infantryman. Since Thelma is in the U.S. Army, she is considered a female version of that: a dough girl.
No guest stars appeared in this episode.