The devil card represents blindness and misconceptions. The black background is the lack of light or understanding. The 2 humans, a male and a female are loosely bound to the stone pillar. They could easily remove their bindings, but stay there by will. The pillar that they are chained to is half of a square, representing the half-truths that they bind themselves to. The torch that the devil is holding is pointing down, and the flame is eating at the torch in a wasteful way, not giving off any light.
The card denotes materialism / physical attraction / animal instincts / vice / lust etc. the appearance of the card in a reading suggest the presence of our passion or obsession. It suggests for us to remove the bad trait that is stopping us from growing or achieving our goal.