This is the story of a skilled weaver falling in love with a girl who works in a steam loom factory. During the Industrial Revolution, skilled craftsman were in the process of being replaced by machinery (in this case, a steam loom) and this led to a series of revolts from the middle class tradesman (see Ned Ludd). For a hand weaver to be with a factory girl would be considered an abomination from the weaver's family and fellow craftsmen, and hence the irony of the song.