During a behind-the-scenes featurette for “Man of Steel,” the filmmakers explained that the “S” in the Superman suit presented a design conundrum. Alex McDowell, the production designer for the film, explained: “The fact that the ‘S’ in a shield exists on the chest of a superhero from another planet is a huge design problem.” Despite the inherent problem, McDowell and co. seized the opportunity to make it a part of Kal-El’s ancestry — a representation of the House of El.
Costume designer Michael Wilkinson explained the symbol’s connection to Krypton:
“You see it on Jor-El, and we see it on Lara as well. When you look at the council costumes, they all have their glyphs, their shield. We looked a lot at medieval heraldry, and symbols of dynasties and guilds and things, so we created our own version of that.“
“Man of Steel” could have simply explained that Superman’s suit was an original creation by himself or his parents, but as Zack Snyder put it, “you have to go and find the ‘why’ of it.” The fantastical elements of the film are well-realized, especially in the opening sequence on the Kryptonian planet. Jor-El (Russell Crowe) always knew his son was meant for greater things, and the symbol of hope on his family crest bridged that belief.