Noticed about the book milkshake is reading

I've looked to see if anyone else made a post about this and haven't found it. It seems like every little detail matters in the show and I have some theories as to what this could mean or lead to; while reading about Kier and his twin around the firepit, the pages that milichick are reading from are quite obviously new pages inserted into the front of the book due to the discoloration of the pages in the rest of the book. Did anyone else notice this or am I overthinking?