The cover depicts the journey of a soul through a man traveling by boat. This man sees Heaven as well as Hell in front of him and he is trying to decide which way to go, as he is the only one who has to make this choice. Likewise, all of us make this choice for us whether we want Heaven ( Happiness and Good ) by doing good to others or we want Hell ( Troubles and Bad ) by doing bad to others. Hence each one of us can steer the boat of our soul towards Heaven or towards Hell by engaging in good or bad karmas respectively.
The Heaven and Hell that he sees in front of him are nothing but an outward projection of the Heaven ( the Good ) and Hell ( the Bad ) that lies within him. It means that most of us have good as well as bad in us and the outside world will look good to us if we choose to be good to others whereas the outside world will look bad to us if we choose to be bad to others, in most cases. Hence the choice is only yours whether you want Heaven or Hell.
The cover also shows that as we keep doing good and raise the level of our soul or our personality, Hell starts leaving us and Heaven starts welcoming us. On the other hand, if we keep doing bad and degrade ourselves more and more, Heaven starts leaving us and we start falling down to Hell. This is why the cover shows more of Hell at the bottom and more of Heaven at the top. The more you rise, the more the Hell is left behind, whereas, the more you fall, the more the Heaven is left behind. It means that if you keep doing good and being positive, a stage will come when this good and positive start killing whatever bad is left in you. Likewise, if you keep doing bad and being negative, a stage will come when this bad and negative starts destroying whatever good is left in you. So make this choice wisely.