I was rereading The Bands of Mourning and in it I think maybe Marasi or Steris says that Wax and Wayne act a lot like brothers, I can't really remember the specifics, but then Wayne said something along the lines of, "I'm fine with being brothers with Wax as long as I'm the handsome one!" (definitely not the exact quote I couldn't find it) And that gave me a callback to The Final Empire, where Kelsier is talking about his actual brother Marsh, and he says "Marsh may be the genius, but I'm the handsome one!" (actual quote there, I saved it)
Did anyone else notice this? Did Brandon Sanderson do this on purpose as a throwback?