A window pane has a comparison to the pain one must pass through for rebirth into a renewed life. The window pane is clear, one can see through to the other side but the barrier or the pane of glass is a facade. I believe the pain from past hurts that one holds on to creates an illusion of security. There is complacency in pain because one begins to think that it is easier to remain punished from the past. If we think of the window pane as the past and what is seen on the other side of the pane are our desires, I think the passing through would not last long. Pass through the pain, it will not last long. The suffering or worse pain is staying in the contemplation stage without ever moving through the pain.
I believe one must cut through the glass or break it to be reborn into a new way of living. The ironic part is how thin the window pane is this in comparison to the reality of how thin pain is from past hurts.
One can see through the glass their hearts desire but one does not want to endure the small amount of pain to get there. Pain does not last always. In pain you find relief. Passing through the pain brings forth a much greater gain, peace.