That horizontal beam added on in Benito's pic should be this circled area. Should be a pretty complicated collection of steel, rebar and concrete as the tower elevator core will sit directly above it.
In most high rises heavy structure around the elevator shafts is just a convenient place to put vertical structural support. I'll be interested to see with this unique build how much or how little structure around the shafts will materialize.
I stand to be corrected, but Walters is doing the rebar framing around steel columns. It's possible Gilbert Steel is suppling the rebar in section to Walter, with Walters place the rebar around the steel column.
With this been push an extra 10 floors, maybe we will see a 100 floor tower on one of the 2 north corners now.
The sun was against me from getting some shots I wanted to shoot and will try it another day