I confess that I found both arts wonderful. The first was released to promote Half-Life 2 and the second was made by fans using Half-Life Alyx's Source 2 verbatim. What do you think? What's your favorite version, the original or Source 2 version released this year? My favorite is the first one for its charm, the second demo like Half-Life 2 would be released nowadays. Original Art was done by Dhabig End and appeared in the book Half-Life 2 - Raising the Bar (Book that shows the development of Half-Life 2); Source 2 art was made jointly by users Komegatze, BrussTrigger THG & Dakashi.
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Definitely original, the second one makes Alyx look like a granny :D Although Gordon seems better.
This was also one of the aspects that made me love ancient art more. I don't understand, it seems that Alyx in the great Source 2, which features 4K textures and the like, can't overcome the incredible quality of Alyx Source 1 from 2004.
Better textures is not everything. In HL:A, her whole face was reshaped. I, too, prefer Alyx from 2004.