At 8:40, Rose asks if it's Jack Hylton she's hearing on the new radio. Jack Hylton (1892-1965) was an English pianist, composer, band leader and impresario. He rose to prominence during the British dance band era, being referred as the "British King of Jazz" and "The Ambassador of British Dance Music" by the musical press.
Hugh Bonneville as the Earl of Grantham comes close to breaking the fourth wall, that is, addressing the audience, when he comments about the idea of getting a "wireless" (radio) for Downton Abbey. His meta line could easily describe television: "I find the whole idea a kind of thief of life, that people should waste hours huddled around a wooden box, listening to someone talking at them, burbling inanities from somewhere else."