AHHHH, that's got to be it, nonnie! I knew about the tricks they used for filming RDJ alongside G Paltrow and I assume maybe they had Deborah kick off her heels for the scenes where she's face to face with Charlie or something. The differences between Charlie and Elden are almost nonexistent, except for the vid of season 2 filming where the height diff looks bigger, harder to ignore.

I roll my eyes at some of the film posters where the principle actor is usually the tallest regardless of actual height, it's the Tom Cruise effect, but I think I can just try to handwave some of the sightline references as much as possible in fic. Unless we really are going to see some change in S2 but you're prob right wrt the cameras and filming to equalize things.