I'm still processing this one and will re-read it this summer for my local GN group. I've heard teasers about the significance of the trillium flower (in regard to Canada/Ontario), but I know I'll hear more about it in group and thus won't research it myself! 
 First off, it's interesting to see Jeff Lemire's people in space. His characters always look related, but they are also usually in forest and fields or seasides...not so much space. The result is fairly enchanting, and I enjoy the effect of the color. His locations usually feel so still and quiet, so space might be more logical than I thought. 
 I really like the time travel aspect and the duality of the story as the protagonists switch places. The issue in which the top is read first then flipped to read the bottom half was my favorite! The mirrored panels! *swoon* I'm wondering if England became steampunk because it was Nika's version...or if we are meant to think William lived in a dirigible-populated London as well...?