I wanted to add a commentary on these two panels (Source unknown -if someone has the link, feel free to give it to me-) that I translated myself with my basic Japanese.
Aside from the dialogue, it seems Eren is connecting the dots between his dreams, potentially the glimpse he got under the Reiss chapel and the logs Grisha left behind. Now that the truth makes sense you can see how strange the dialogue became and how suspicious some panels are:
Eren’s change in pronouns and familiarity: as pointed in the dialogue, he started using “私 (watashi)” instead of “俺 (ore)” as a first person pronoun, on top of him getting awfully familiar with the titan that ate his mother, as well as his father’s first wife, despite the two of them having never interacted before.
Mikasa, Armin and the cell’s bars: notice how awfully different Mikasa looks here? Not only that but she shares the same hairstyle as Eren’s grandmother, on top of her having the same expression of concern. On the other hand, Armin wears exactly the same clothes than the ones he had before departing to Wall Maria. That’s one of the most blatant details than the one that really bothered me when I saw the two pages: the crossing bars. Eren, Mikasa and Armin have been crossed by these bars and I hardly doubt that’s an effect to highlight their faces since several instances clearly depicted a demarcation between the cell and its’ exterior (Sannes and Hange). The bars are almost… merging with their faces.
These two details lead me to believe that Eren was thrown in a cell, alone, piecing the information in his mind. While doing that, the coordinate slowly began to take effect on him, almost as if he was possessed by Grisha. In fact, I think his memories are becoming so jumbled he pieces his information with Grisha’s.
He’s good for a coordinate delirium during his imprisonment.
P.S.: I’ve seen some people comparing Armin’s look to Faye and I wouldn’t be surprised if portions of Faye were reflected in the Armin we’re seeing. That would explain why he’d notice Eren’s sudden change in pronouns, since Grisha also used “俺 (ore)” when he was a kid.