Most of our understanding of Victor's appearance comes from Walton. When his sailors first rescue Victor from the iceberg, Walton writes to his sister that:
His limbs were nearly frozen, and his body dreadfully emaciated by fatigue and suffering. I never saw a man in so wretched a condition.
But as time goes on, Walton increasingly sees Victor as a sensitive, refined, and physically attractive man. At first, Victor's eyes are usually wild, but Walton states:
There are moments when, if anyone performs an act of kindness towards him or does him any the most trifling service, his whole countenance [face] is lighted up, as it were, with a beam of benevolence and sweetness that I never saw equalled. But he is generally melancholy and despairing, and sometimes he gnashes his teeth.
Walton goes on to tell his sister that Victor's
manners are so ... gentle that the sailors are all interested in him ... I begin to love him as a brother, and his constant and deep grief fills me with sympathy and compassion. He must have been a noble creature in his better days, being even now in wreck so attractive and amiable.
The lonely Walton increasingly warms up to Victor and writes to his sister:
I have found a man who, before his spirit had been broken by misery, I should have been happy to have possessed as the brother of my heart.
Walton idealizes him and also mentions the beauty of his voice:
a penetration into the causes of things, unequalled for clearness and precision; add to this a facility of expression and a voice whose varied intonations are soul-subduing music.
Walton's description of Victor is important for several reasons. First, as our first impression of Victor, it builds reader sympathy for this character. He is intuitive, delicate, once beautiful, suffering, a refined European from the educated classes. We are inclined to listen to his story with sympathy, and it is likely we will be biased in his favor.
Second, he fits the mold of the Byronic hero, the suffering soul tortured by a secret grief and refined, poetic sensibilities. Third, Walton's favorable response to his new friend's good looks starts to establish the importance of physical appearance, a major theme of the novel. Because Victor fits Walton's preconceived notions of looking like a sensitive European, Walton is drawn toward him. It is very possible that Walton's positive response to Victor's physical beauty (or the romantic wreck of it) leads Walton to conclude that Victor's soul is purer than it is. As we will find as Victor tells his story, he has treated the creature he made with deep insensitivity and rejection and has not been a good person towards him. Finally, we perceive how the creature's outward appearance of ugliness leads Walton to reject it, showing the difficulties faced when an outwardly monstrous form covers a soul that wants to be good.