Well I found a really comprehensive article on this coin on the PCGS website.The sculptor/engraver Sherl Joseph Winter claims she used various photos of immigrants arriving,and used the same year (1913) skyline as on the obverse.Here is the quote:
"The scene is of a later date (shows the Woolworth Bldg., a landmark in 1913), and the same skyline was used on the reverse. Sherl J. Winter and I agreed to use the same one. The same ship also sailed by the statue in 1913"
http://www.pcgs.com/articles/article...universeid=313