Glass is about the difficult process of gathering the fragmented pieces of a broken heart. The song expresses feelings of paranoia, confusion and resentment when someone close to you has severely and unexpectedly broken your trust. When trust is destroyed in a heart-shattering way, defences go up and it becomes second nature to question the intentions of other people you consider close.
Although lyrically melancholic, Glass has energy and heart in its musical delivery. The solidarity and confidence within the music aid in obscuring the heartbreak so blatant in the lyrics creating the crossroad of heartbreak and hope. Glass shares glimmers of hope that the pieces can be put back together with the reminded sting of mishandling these sharp pieces.