Board Thread:Manga/@comment-5774380-20160908231942/@comment-26932251-20160909040616

Another thing I want to point out, that photo, even though we can't see it because of the stylistic decision of the manga, is most likely in color.

Despite the 18th century style dress of the people in the photo, you'll notice that Levi and Hange refer to the photograph as being 'like a painting' instead of like a drawing. We know from when Moblit sketched Eren's head that was missing skin that the Wall people have a culture of graphite drawing and we can also see elsewhere that they have painting which I think we can safely assume would be in color.

Long story short, if the photo wasn't in color then I don't think they would compare it to a painting. To them a monochromatic image would be more akin to graphite drawings.

This is an important distinction because color photography is significantly further along the 'tech tree' than just monochromatic photography.

Also, the image can't be ruled out as possibly being a print of a digital photograph, all that Grisha says is that it was light cast onto a 'special material' which could refer to film but it could also refer to the surface of a digital sensor or even some kind of future technology that doesn't exist yet in our world.