Symbolism, Imagery, Allegory
The clock, bought in Europe by Big Daddy and Big Mama, says that yes, you've got time. It chimes, and Brick says, "nice peaceful-soundin' clock, I like to hear it all night…" (II.85.515); in this way, we hear death's approach yet again. Its presence in the household evokes the memory of Big Daddy's trip to Europe and the corruption he found there, but to Brick it tolls the peaceful march of time.
The emphasis on time is also important because, as play watchers, we are much more concerned with when this play will end or at least when there'll be a break so that we can go and get more milk duds. We get a little anxious with all the references to and attention placed upon time, and we sense the end of the play in perhaps the same way that Big Daddy senses death. Also, a strategically placed clock in literature always compels us to pay attention to the time throughout the play, both on stage and in the historical context.