The man is holding a pickaxe
, which he has resting on his shoulder.
The pointed edge is most often used to break up rocky surfaces or other hard surfaces such as concrete or hardened dried earth. The large momentum of a heavy pickaxe, combined with the small contact area, makes it very effective for this purpose. Originally used as agricultural tools as far back as prehistoric cultures, picks have also served for tasks ranging from mining to warfare.
In the card, it just looks like he is resting. The way he has his hand on his forehead can be viewed as him looking out for something, but that is generally associated with a flat hand. His hand is sort of fisted, which makes me think that he might be just wiping sweat off his brow, or he's got a headache.