I had a theory that a skillful alchemist like Hohenheim could alter physical features, but that would not account for resemblance.
Hohenheim choose bodies with similar features like his old one.
Envy is lying. He wants to show Edward that he is his brother, and so altered his features to resemble what Edward would look like as an adult.
The second one is more in line to Anime1's portrayal of Envy as Edward's dark doppelganger, the person Edward almost became if he lacked Trisha, Al, and Winry in his life.