"Last Supper" represents the last stage of mind/cosmos evolution, the last stage of de-construction of the self/mind.
The house/mind is destroyed, it is but a ruin gained by Nature/Chaos.
This is the last step before the Return to the Origin, where/when Nature is the law, which we mankind are part of. It is the end of a cycle, the closure of the Circle, the reunion with our Pure and Divine Essence. It is one step before Contact, the rejoining with the World, the end of dualism.
"Last Supper" represents the final and conclusive defeat, the failure of the attempt of controlling the World, Nature and others.
The self/man/cosmos sitting alone, desolate, dejected, resigned, is defeated.
Time/table is suspended; the three spatial dimension are being gained by Nature. Chaos and Life are spheric, are all-directional.
The three expiring candles are the three monotheistic religions.