The suit is the same and Samus show more muscles like in SR, the difference are the heels, the bracelet the reduced breast, the hairstyle (who is more inspired by Zero Mission) and the face (who I might add, is probably unfinished, like alot of human characters faces). It's a fusion of SR design and her Smash 4 design with a touch off the Zero Mission design.
Honestly, I feel like the only reason Samus didn't get her SR design was because she was one of the first character to be made for Ultimate. Due to this and SR not being announced at the time if I remember correctly, Sakurai decided to keep her Smash 4 design due to lack of new Metroid game at the time. Sometime later, as it was ZSS turn, the Smash team probably got a few notes from the SR team and they either redesigned ZSS to be more like her SR design, or just got her design early enough to start working on it.
In all cases, ZSS wasn't done in time for the E3 trailer, and she isn't alone, loads of characters have weird or bad face that peoples have already point out.
Also, muscles > boobs, actual fact right here.