Dismembered Soldier

In this image we see the harrowing sight of a dismembered body of a man. He's still clutching a sword which is clearly broken but importantly, still being tightly grasped in the dead man's hand.

His arms are bloodied and we are not spared what we might imagine being the insides of his severed arm. His head is severed too but we're spared any detail here...possibly because the head is meant to be the bust that it so clearly is. This is discussed in the 'Bust' section.

Though the head is the bust of a statue, I think we can see that Picasso once again, instilled a multiple role for this part of the soldier. 

The Warrior Soldier

The obvious interpretation of this figure is exactly what we see here... a soldier, holding a broken sword...dismembered and dead. 

Whole essence of Guernica, the painting, is to bring to our attention the hideous results of a bombardment of a small town where predominantly were all but soldiers, women, children, the elderly. 

I doubt Picasso's primary purpose for this figure is to depict a fallen soldier in battle though.

The Republican Army

This figure is much more likely meant to symbolise the fall of the Republican Army and political movement. 

The broken and disjointed depiction we see here is, in my view far more aligned as a metaphor to a broken movement. And that movement is given an identity by the sword that it involves. Still clenched tightly, broken, in the dead arm that wealded it.

Crucifixion

The position of the arms, outstretched in this way invoke a reflection of Christ on the the Cross. Looking closely at the soldier's left hand, we can see a feint indication of a puncture wound in the palm of his hand. Possibly a sign of the stigmata.

Further evidence of this being Christ can be drawn from the original construction drawings when Picasso first began contructing the composition. We can see a male figure, deceased in the same vicinity as the current soldier lies. His posture very much a combination of Christ having been brought down from the Cross and also with outstretched arms as on the crucifix.