Lu wears a brooch of a design featuring two cherries. This references Helena's lines from 'A Midsummer Night's Dream': Act III Scene 2 - "So we grew together, / Like to a double cherry - seeming parted / But yet an union in partition - / Two lovely berries molded on one stem." It may be a comment on Lu and Frank's working relationship.
The title, "O Thou Invisible Spirit of Wine" comes from 'Othello': Act II Scene 3.
The 'Rosie Jones' featured is actually the comedian.