I think the poster is giving Nolan too much credit. Nolan only worked on the re-writes of the script. Any other work he did on "Man of Steel" was halted when he started production on "The Dark Knight Rises". Otherwise this is Snyder's film 100 percent.
Well to be fair it does look like Nolan had an influence on the look and style of the film as well (and thankfully so).
Without him producing, I imagine Snyder's Superman would have been MUCH more flashy and colorful and over the top.