On one level, the significance of this card is obvious. If we are not careful, The machinery of life can grind us down until nothing is left but an unending succession of duties, responsibilities and obligations. When this happens, we lose the capacity to relax and enjoy life. We forget the importance of setting aside time to play or simply to be in order to rejuvenate our spirit. Eventually, We end up succumbing to physical and spiritual exhaustion.
On a deeper level, this card warns us against reacting mechanically, from preconceived notions of how things should be. According to the LWB, "A man who lives through conscience becomes hard. A man who lives through consciousness remains soft." I don't think the intent here is that we should be able to do whatever we want regardless of consequences. I believe the intent here is that we should avoid the rigid application of concepts of 'right' and 'wrong,' or any concepts for that matter, in circumstances where they may not apply. That's where 'consciousness' is necessary. 'Consciousness' refers to awareness. When we can put the thinking, judging mind aside and approach a situation with open awareness, we can respond to that situation more appropriately, with true sensitivity to its unique characteristics.
This is no different than hugging a tree. If you see the tree as just another tree, rather than as the unique lifeform that particular tree truly is, you will never feel it hug back.