The creature Gollum is really a reduced Hobbit. Gollum is a hobbit reduced to an abstraction, a kind of shadow. Abstract eyes and abstract hands are his two aspects. The Dark Lord has wounded Gollum. This wounding makes Gollum a walking shadow, a shadow of the soul of Smeagol. Gollum is a two dimensional shadow. In Fellowship we often see in characters a shadow side.
above: top..the fingers of the witch king and beneath the hand of Gollum
Symbolism in fingers
Wraiths have extended fingers, a symbol of ego. The fingers become instruments of an evil will; they probe, take and stab. The creature Gollum is really a reduced Hobbit. All those aspects that endear us to Hobbits have been stripped away. Gollum is reduced to an abstraction, a kind of shadow. Abstract eyes and abstract hands are his two aspects. The Nazgul have been humiliated in their mutilation, evil has turned them into parodied kings. So Gollum is a parody of a hobbit. This makes Gollum, as an agent of evil, more compliant to the master but breeds a kind of resentment to the master as well. Cowering yet resentful. The dual aspect of Gollum can make him a faithful servant or a duplicitous rogue. The Nazgul bear the wound of being taken by the dark lord and in this they seek to wound those they must find. The Dark Lord too has wounded Gollum. This wounding makes Gollum a walking wounded shadow of the soul of Smeagol. Gollum too is compelled to seek and wound.
Temptation in shadow When Galadriel is fighting the temptation of the freely offered ring she is seen as a battleground between light and shadow. At once the shadow side seems to almost take her over and her eyes enlarge and become almost 'gollum like.'
Gollum is really a kind a frozen moment of temptation. The large eyes and darkened body refer to the victory of temptation, of darkness.