I thought it was supposed to represent an inverted space ship/shuttle with rockets firing, but I have honestly no clue what it represents. It appeared on the previous blue prototype and was larger, which leads me to believe that it serves mainly as an illumination source when working in a Martian storm.
From a different article,
'In 2014, NASA unveiled the winner in a contest, open to the public, to select the appearance of the outer covering of the Z-2 next-generation spacesuit. The winning design, nicknamed "Technology," sports electroluminescent stripes (right) for better visibility in darkness.'
I seriously dig the design. The pants look like my Vertx pants, gusseted, tacticool and shit!