Board Thread:Manga/@comment-5774380-20160808233126/@comment-27441457-20160809222012

I don't think Eren's dream in the anime holds as much significance now as it did when the series premiered. I don't have an exact quote, but I recall Isayama saying that the huge popularity of the anime's first season influenced him to make some changes on how he plans to ultimately end his story. Titan Armin might not have been an idea Isayama was considering back when the anime was being produced.

But in any case, that's indisputably the Smiling Titan we see in his dream. Same nose, same cheek lines, nearly identical teeth (some design aspects are given more detail than others depending on the shot), and Armin's Titan had a completely different mouth that more resembled Armin's mouth after his lips were burnt off.