Here’s (most of) the first verse from Cassandra Jenkins’ song Petco:
Outside my window I saw two doves
Wrapped up in filthy and true love
The walls are blushing landlord pink
The dishes pile up…
Unconsciously, the mind fills in the rhyme: The dishes pile up in the sink. But the real lyric is:
The dishes pile up, my heart sinks
Its a subtle subversion of expectation. What does such a subversion do? Its like walking up a staircase, your mind attuned to the height of each step. You can jog up the stairs without thinking - until one step is just slightly off and you trip. In other words, what such a subversion does is break the listener out of their reverie.
The dishes pile up in the sink would be a fine lyric. It already paints an image of someone too weighed down to answer the everyday asks of life. But say the actual line aloud: The dishes pile up, my heart sinks. That comma adds a pause that wouldn’t otherwise be there. An extra pause, an extra beat of quiet, a heaviness.
And because the phrase “pile up in the sink” is never fulfilled, the feeling of absence lingers. You can almost imagine the speaker at the sink, water running over, when it hits them: I’m unhappy. They meant to do the dishes - and they meant to finish the line - but they never did.