there are some other materials that might work better at getting closer to the original. I feel like there's too much 'bump' in it, maybe something a touch smoother (or lower the bump on the materials)..just my thought. As for getting a modern look; maybe something like an IPOD in her hand (I think there's some in freebies), modern sunglasses (Gerald Day has some sunglasses), possibly even an earphone (BVH Swat comes with a multitude of 'extra's) if you want to bring it into this century. Put these on the model prior to importing into Bryce, and that might update it some.
Another thing is to vary the pose some. Maybe raise one foot on the Y axis in Poser (in the original, you can see her preparing to step off the last step), or move an arm, turn her head one way or another, just something that gives it some 'motion'..
Not an expert on Hopper, but I did live in one of his paintings for awhile..;)

I wish I'd said that.. The Staircase Wit

anahl nathrak uth vas betude doth yel dyenvey..;)